matrix bridge: Update & improve README.md.
MODIFY
zulip/integrations/matrix/README.md
zulip/integrations/matrix/README.md
@@ -18,22 +18,37 @@ Hence, this can also be used as a IRC <--> Zulip bridge.
## Steps to configure the Matrix bridge
+To obtain a configuration file template, run the script with the
+`--write-sample-config` option to obtain a configuration file to fill in the
+details mentioned below. For example:
+
+* If you installed the `zulip` package: `zulip-matrix-bridge --write-sample-config matrix_bridge.conf`
+
+* If you are running from the Zulip GitHub repo: `python matrix_bridge.py --write-sample-config matrix_bridge.conf`
+
### 1. Zulip endpoint
-1. Create a generic Zulip bot, with a full name like `IRC Bot`.
-2. Subscribe the bot user to the stream you'd like to mirror your IRC
+1. Create a generic Zulip bot, with a full name like `IRC Bot` or `Matrix Bot`.
+2. Subscribe the bot user to the stream you'd like to bridge your IRC or Matrix
channel into.
-3. Enter the bot's `zuliprc` details (`email`, `api_key`, and `site`)
- into `matrix_bridge_config.py`
-4. Enter the destination topic, stream and site in `matrix_bridge_config.py`
+3. In the `zulip` section of the configuration file, enter the bot's `zuliprc`
+ details (`email`, `api_key`, and `site`).
+4. In the same section, also enter the Zulip `stream` and `topic`.
### 2. Matrix endpoint
1. Create a user on [matrix.org](https://matrix.org/), preferably with
a formal name like to `zulip-bot`.
-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`
+2. In the `matrix` section of the configuration file, enter the user's username
+ and password.
+3. Also enter the `host` and `room_id` into the same section.
+
+## Running the bridge
+
+After the steps above have been completed, assuming you have the configuration
+in a file called `matrix_bridge.conf`:
+
+* If you installed the `zulip` package: run `zulip-matrix-bridge -c matrix_bridge.conf`
-After the steps above have been completed, run `python matrix_bridge.py` to
-start the mirroring service.
+* If you are running from the Zulip GitHub repo: run `python matrix_bridge.py -c matrix_bridge.conf`
## Caveats for IRC mirroring

matrix bridge: Update & improve README.md.