Improve readme for Synapse module

Author: hughns

synapse/README.rst

@@ -1,14 +1,30 @@
-==============================================
-Matrix Synapse module which implements MSC3886
-==============================================
+Matrix Synapse module which implements MSC3886 Simple HTTP rendezvous server
+============================================================================
 
-Usage::
+This is an implementation of `MSC3886
+<https://github.com/matrix-org/matrix-spec-proposals/pull/3886>`_ for `Synapse
+<https://github.com/matrix-org/synapse>`_.
+
+=====
+Usage
+=====
+
+1. Install the module to make it available to your Synapse environment::
 
     pip install matrix-http-rendezvous-synapse
 
-In your homeserver.yaml::
+2. Enable the module in your homeserver.yaml::
 
     modules:
       - module: matrix_http_rendezvous_synapse.SynapseRendezvousModule
         config:
-          prefix: /rendezvous
+          prefix: /_synapse/client/org.matrix.msc3886/rendezvous
+
+3. Make the module available at the actual API endpoint in the Client-Server API by adding this to your homeserver.yaml::
+
+    experimental_features:
+      msc3886_endpoint: /_synapse/client/org.matrix.msc3886/rendezvous
+
+4. Run Synapse with the asyncio reactor enabled::
+
+    SYNAPSE_ASYNC_IO_REACTOR=1 python -m synapse.app.homeserver