Content proposal

## 📝 Content Proposal

### Synopsis
A clear and concise description of the content you will be contributing.

### Content type

- [x] Guide
- [ ] Tutorial
- [ ] Example
- [ ] Translation
- [ ] Other (please specify)

### Process
Read the [contributing guide](https://amp.dev/documentation/guides-and-tutorials/contribute/contribute-documentation/?format=websites), then create a copy of [this template](https://docs.google.com/document/d/18i_lbQ-h-auYW2SwbWRuuu2_xhtU5XrjXlcCtj0sNeY/edit?usp=sharing) and fill in the proposal and outline sections. When you’ve finished, add the link to this issue and check the box for step one. A member of the AMP team will assign the ticket to themselves and work as your reviewer through the remaining steps. Thanks for contributing to AMP!

- [ ] 1. Proposal created: ``.
- [x] 2. Proposal approved.
- [ ] 3. Draft complete.
- [ ] 4. Draft approved.
- [ ] 5. Pull request submitted.
- [ ] 6. Pull request approved!

Start with the linked AMP contributing guide and the Google Docs proposal template. Complete the proposal and outline for the guide, then use the issue checklist to track the draft, approvals, and pull request; done means the guide is approved and its pull request is submitted and approved.

Written by the indexing model from the issue text.