Fix use of headers. (#30)

There should only be one title per doc.

CODE_OF_CONDUCT.md

@@ -107,13 +107,13 @@ spaces:
 If you have questions, please feel free to ask on our Discourse Forum, Discord
 Chat, or contact any member of the conduct team directly.
 
-# Conduct team
+## Conduct team
 
 At present, the [core team](docs/project/evolution.md#core-team) will serve as
 the conduct team. We expect to establish a dedicated conduct team if and when
 the project grows, along with more communication systems for reports.
 
-## Reporting conduct
+### Reporting conduct
 
 If you believe someone is violating the code of conduct, you can always report
 it to the conduct team by emailing all members of the conduct team. **All
@@ -137,7 +137,7 @@ event information will include detailed contact information for that event. In
 person reports will still be kept confidential exactly as above, but also feel
 free to (anonymously if needed) email the conduct team.
 
-## Filing a report
+### Filing a report
 
 Reports can be as formal or informal as needed for the situation at hand. If
 possible, please include as much information as you can. If you feel
@@ -153,7 +153,7 @@ comfortable, please consider including:
 - If you believe this incident is ongoing.
 - Any other information you believe we should have.
 
-## What happens after contacting the conduct team?
+### What happens after contacting the conduct team?
 
 You will receive a reply from the conduct team acknowledging receipt within 1
 business day (and we will aim to respond much quicker than that).
@@ -197,7 +197,7 @@ statement about the incident. If that’s the case, the identities of anyone
 involved will remain confidential unless instructed otherwise by those
 individuals.
 
-## Appealing
+### Appealing
 
 Only permanent resolutions (such as bans) or requests for public actions may be
 appealed. To appeal a decision of the conduct team, contact the
@@ -213,7 +213,7 @@ Code of Conduct, the conduct team itself, or the appropriateness of responses in
 general, but **please** refrain from mentioning specific facts about cases
 without the explicit permission of all parties involved.
 
-# Enforcement action guidelines
+## Enforcement action guidelines
 
 The conduct team, moderators, and event organizers have the right and
 responsibility to remove, edit, or reject comments, commits, code, wiki edits,
@@ -249,7 +249,7 @@ involved:
     - **Behavior:** Demonstrating a pattern of violation of the code of conduct.
     - **Action:** A permanent ban from use of Carbon's community spaces.
 
-# Acknowledgements
+## Acknowledgements
 
 This code is based on the
 [LLVM Code of Conduct](https://llvm.org/docs/CodeOfConduct.html), the

CONTRIBUTING.md

@@ -22,9 +22,9 @@ We also encourage anyone interested in contributing to check out all the
 information here in our contributing guide, especially the
 [guidelines and philosophy for contributions](#guidelines-and-philosophy-for-contributions)
 
-# Ways to contribute
+## Ways to contribute
 
-## Help comment on proposals
+### Help comment on proposals
 
 If you're looking for a quick way to contribute, commenting on proposals is a
 way to provide proposal authors with a breadth of feedback. The "Evolution >
@@ -36,7 +36,7 @@ nearing the decision process. For more about the difference, see the
 When giving feedback, please keep comments positive and constructive. Our goal
 is to use community discussion to improve proposals and assist authors.
 
-## Help contribute ideas to Carbon
+### Help contribute ideas to Carbon
 
 If you have ideas for Carbon, we encourage you to discuss it with the community,
 and potentially prepare a proposal for it. Ultimately, any changes or
@@ -49,12 +49,12 @@ eventually implemented. A good starting point is to read through the
 [evolution process](docs/project/evolution.md). We encourage discussing the idea
 early, before even writing a proposal, and the process explains how to do that.
 
-## Help implement Carbon's design
+### Help implement Carbon's design
 
 Eventually, we will also be working toward a reference implementation of Carbon,
 and are very interested in folks joining in to help us with it.
 
-## Help address bugs
+### Help address bugs
 
 As Carbon's design (and eventually implementation) begin to take shape, we'll
 inevitably end up with plenty of bugs. Helping us triage, analyze, and address
@@ -62,9 +62,9 @@ them is always a great way to get involved. When we have the bug tracker(s) set
 up for this, we'll update this section with ideas of how to find these and get
 started.
 
-# How to become a contributor to Carbon
+## How to become a contributor to Carbon
 
-## Contributor License Agreements (CLAs)
+### Contributor License Agreements (CLAs)
 
 We'd love to accept your documentation, pull requests, and comments! Before we
 can accept them, we need you to cover some legal bases.
@@ -87,14 +87,14 @@ accept your documents, comments and pull requests.
 CLA can be accepted as Carbon contributions: this covers the GitHub repository,
 GitHub issues, Google Docs, Discourse Forums, and Discord Chat.
 
-### Future CLA plans
+#### Future CLA plans
 
 At present, we are using Google's CLA. In the future, we expect the Carbon
 ownership and IP to formally transfer from Google to a Carbon-specific
 foundation or other neutral third-party. When that happens, the foundation will
 take ownership of providing a CLA.
 
-## Collaboration systems
+### Collaboration systems
 
 We use a few systems for collaboration which contributors should be aware of.
 Membership is currently invite-only.
@@ -138,12 +138,12 @@ the Code of Conduct.
       [Google Group](https://groups.google.com/g/carbon-lang-contributors) used
       for access.
 
-## Contribution guidelines and standards
+### Contribution guidelines and standards
 
 All documents and pull requests must be consistent with the guidelines and
 follow the Carbon documentation and coding styles.
 
-### Guidelines and philosophy for contributions
+#### Guidelines and philosophy for contributions
 
 - For **both** documentation and code:
 
@@ -184,9 +184,9 @@ follow the Carbon documentation and coding styles.
   - Keep in mind that code contribution guidelines are incomplete while we start
     work on Carbon, and may change later.
 
-# Style
+## Style
 
-## Google Docs and Markdown
+### Google Docs and Markdown
 
 Changes to Carbon documentation follow the
 [Google developer documentation style guide](https://developers.google.com/style).
@@ -199,21 +199,21 @@ Other style points to be aware of are:
 - Always say "Discourse Forum" and "Discord Chat" to avoid confusion between
   systems.
 
-## Other files
+### Other files
 
 If you're not sure what style to use, please ask on Discourse Forums.
 
-# License
+## License
 
 A license is required at the top of all documents and files.
 
-## Google Docs
+### Google Docs
 
 Google Docs all use
 [this template](https://docs.google.com/document/d/1sqEnIWWZKTrtMz2XgD7_RqvogwbI0tBQjAZIvOabQsw/template/preview).
 It puts the license at the top of every page if printed.
 
-## Markdown
+### Markdown
 
 Markdown files always have at the top:
 
@@ -229,13 +229,13 @@ For example, see the top of
 [CONTRIBUTING.md](https://github.com/carbon-language/carbon-lang/raw/master/CONTRIBUTING.md)'s
 raw content.
 
-## Other files
+### Other files
 
 Every file type uses a variation on the same license text ("Apache-2.0 WITH
 LLVM-exception") with similar formatting. If you're not sure what text to use,
 please ask on Discourse Forums.
 
-# Acknowledgements
+## Acknowledgements
 
 Carbon's Contributing guidelines are based on
 [Tensorflow](https://github.com/tensorflow/tensorflow/blob/master/CONTRIBUTING.md)