Matrix: Update documentation and add requirements.txt.

zulip/integrations/matrix/README.md

@@ -1,19 +1,39 @@
 # Matrix <--> Zulip bridge
 
-This also enables a Zulip topic to be federated !
+This acts as a bridge between Matrix and Zulip. It also enables a Zulip topic to be federated.
 
 ## Usage
 
+### For IRC bridges
+
+Matrix has been bridged to the listed
+[IRC networks](https://github.com/matrix-org/matrix-appservice-irc/wiki/Bridged-IRC-networks),
+where the 'Room alias format' refers to the `room_id` for the corresponding IRC channel.
+
+For example, for the freenode channel `#zulip-test`, the `room_id` would be
+`#freenode_#zulip-test:matrix.org`.
+
+Hence, this can also be used as a IRC <--> Zulip bridge.
+
+## Steps to configure the Matrix bridge
+
 ### 1. Zulip endpoint
 1. Create a generic Zulip bot
 2. (don't forget this step!) Make sure the bot is subscribed to the relevant stream
-2. Enter the bot's email and api_key into matrix_bridge_config.py
-3. Enter the destination subject and realm into matrix_bridge_config.py
+2. Enter the bot's email and `api_key` into `matrix_bridge_config.py`
+3. Enter the destination subject, realm and site in `matrix_bridge_config.py`
 
 ### 2. Matrix endpoint
-1. Create a user
-2. Enter the user's username and password into matrix_bridge_config.py
-3. Enter the host and room_id into matrix_bridge_config.py
+1. Create a user on [matrix.org](https://matrix.org/)
+2. Enter the user's username and password into `matrix_bridge_config.py`
+3. Enter the host and `room_id` into `matrix_bridge_config.py`
 
 After the steps above have been completed, run `python matrix_bridge.py` to
 start the mirroring.
+
+## Note
+
+There are certain
+[IRC channels](https://github.com/matrix-org/matrix-appservice-irc/wiki/Channels-from-which-the-IRC-bridge-is-banned)
+where the messages from Zulip cannot be forwarded to
+IRC due to a ban on the Matrix bot.

zulip/integrations/matrix/requirements.txt

@@ -0,0 +1 @@
+matrix-client-0.2.0