Merge branch 'deprecated' into 'master'

Indicate that `extern/rest` is the deprecated method

See merge request documentation/docs/dev!999

docs/api/v3/rest.md

@@ -46,7 +46,7 @@ Here, we have a different *end-point URL* (line 1) along with a different *authe
 
 As we proceed through this chapter, we will consider different API features. When choosing which features to use, you may wish to consult back to this compatibility matrix.
 
-| End-Point URL | `civicrm/ajax/*` | `extern/rest.php` | `WP REST` |
+| End-Point URL | `civicrm/ajax/*` | `extern/rest.php`(deprecated) | `WP REST` |
 |--|--|--|--|
 | APIv3                             | **Yes**              | **Yes**                | **Yes** |
 | APIv4                             | **Yes**              | No                     | No  |