Add documentation.

docs/config.md

@@ -193,3 +193,14 @@ You can then do
 ```
 curl "http://localhost:4000/api/pleroma/admin/invite_token?admin_token=somerandomtoken"
 ```
+
+## Pleroma.Web.Federator
+
+* `max_jobs`: The maximum amount of parallel federation jobs running at the same time.
+
+## Pleroma.Web.Federator.RetryQueue
+
+* `enabled`: If set to `true`, failed federation jobs will be retried
+* `max_jobs`: The maximum amount of parallel federation jbos running at the same time.
+* `initial_timeout`: The initial timeout in seconds
+* `max_retries`: The maximum number of times a federation job is retried