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