Update composer docs (#1666)

* Update composer docs

OSX issue has been fixed for later versions

* Update composer/content.md

Co-Authored-By: Rob <[email protected]>

Co-authored-by: Rob <[email protected]>

composer/content.md

@@ -67,7 +67,7 @@ $ eval $(ssh-agent); \
   %%IMAGE%% install
 ```
 
-**Note:** This currently does not work on OSX, see [docker/for-mac#410](https://github.com/docker/for-mac/issues/410).
+**Note:** On OSX this requires Docker For Mac v2.2.0.0 or later, see [docker/for-mac#410](https://github.com/docker/for-mac/issues/410).
 
 When combining the use of private repositories with running Composer as another user, you might run into non-existent user errors (thrown by ssh). To work around this, simply mount the host passwd and group files (read-only) into the container: