Updates the placeholder in the curl examples of the API docs for
the user authentication line (-u) to be EMAIL_ADDRESS:API_KEY.
Adds text to the top of the curl tab about the user authentication
line with links to the curl man doc and the authorization header
section of the HTTP headers article.
If the endpoint does not have the user auth line (e.g., fetching
an API key in dev and production), then the text is not added to
the curl tab.
Fixes#479.
Updates `.md` files in api_docs/ to use "stream" instead of "channel"
for descriptive text, with the exception of the API changelog file.
Part of stream to channel rename project.
For endpoints with a `type` parameter to indicate whether the message
is a stream or direct message, `POST /typing` and `POST /messages`,
adds support for passing "direct" as the preferred value for direct
messages, group and 1-on-1.
Maintains support for "private" as a deprecated value to indicate
direct messages.
Fixes#24960.
- Updates `.prettierignore` for the new directory.
- Updates any reference to the API documentation directory for
markdown files to be `api_docs/` instead of `zerver/api/`.
- Removes a reference link from `docs/documentation/api.md` that
hasn't referenced anything in the text since commit 0542c60.
- Update rendering of API documentation for new directory.
