Document errors more

docs/index.rst

@@ -148,17 +148,26 @@ not exist).
 
 `MastodonFileNotFoundError` and `MastodonNetworkError` are IO errors - could be you
 specified a wrong URL, could be the internet is down or your hard drive is
-dying. They inherit from MastodonIOError, for easy catching.
+dying. They inherit from `MastodonIOError`, for easy catching. There is a sub-error
+of `MastodonNetworkError`, `MastodonReadTimeout`, which is thrown when a streaming
+API stream times out during reading.
 
 `MastodonAPIError` is an error returned from the Mastodon instance - the server
 has decided it can't fullfill your request (i.e. you requested info on a user that
-does not exist).
+does not exist). It is further split into `MastodonNotFoundError` (API returned 404)
+and `MastodonUnauthorizedError` (API returned 401). Different error codes might exist,
+but are not currently handled separately.
+
+`MastodonMalformedEventError` is raised when a streaming API listener receives an
+invalid event. There have been reports that this can sometimes happen after prolonged
+operation due to an upstream problem in the requests/urllib libraries. 
 
 `MastodonRatelimitError` is raised when you hit an API rate limit. You should try 
 again after a while (see the rate limiting section above).
 
 `MastodonVersionError` is raised when a version check for an API call fails.
 
+
 Return values
 -------------
 Unless otherwise specified, all data is returned as python dictionaries, matching