* DOCS: add mention of swagger api reference
It's(swagger api link) mentioned vaguely in the FAQ but IMHO missing from API usage page.
* Add warning to avoid template mismatches
Related to https://github.com/go-gitea/gitea/issues/9320
## Customizing Gitea pages
The `custom/templates` folder allows changing every single page of Gitea. Templates
-to override can be found in the [`templates`](https://github.com/go-gitea/gitea/tree/master/templates) directory of Gitea source. Override by
+to override can be found in the [`templates`](https://github.com/go-gitea/gitea/tree/master/templates) directory of Gitea source (Note: the example link is from `master` branch. Make sure to copy templates from same release you are using). Override by
making a copy of the file under `custom/templates` using a full path structure
matching source.