Adding upstream version 0.8.9.

Signed-off-by: Daniel Baumann <daniel@debian.org>

docs/services/matrix.md

@@ -0,0 +1,44 @@
+# Matrix
+
+!!! note Usage of the `title` parameter
+    Do note that Matrix will discard any information put in the `title` parameter as the service has no analogue to a
+    a title. Instead, use a custom message format to supply your wanted title as part of the message.
+
+## URL Format
+
+*matrix://__`user`__:__`password`__@__`host`__:__`port`__/[?rooms=__`!roomID1`__[,__`roomAlias2`__]][&disableTLS=yes]*
+
+--8<-- "docs/services/matrix/config.md"
+
+## Authentication
+
+If no `user` is specified, the `password` is treated as the authentication token. This means that no matter what login
+flow your server uses, if you can manually retrieve a token, then Shoutrrr can use it.
+
+### Password Login Flow
+
+If a `user` and `password` is supplied, the `m.login.password` login flow is attempted if the server supports it.
+
+## Rooms
+
+If `rooms` are *not* specified, the service will send the message to all the rooms that the user has currently joined.
+
+Otherwise, the service will only send the message to the specified rooms. If the user is *not* in any of those rooms,
+but have been invited to it, it will automatically accept that invite.
+
+**Note**: The service will **not** join any rooms unless they are explicitly specified in `rooms`. If you need the user
+to join those rooms, you can send a notification with `rooms` explicitly set once.
+
+### Room Lookup
+
+Rooms specified in `rooms` will be treated as room IDs if the start with a `!` and used directly to identify rooms. If
+they have no such prefix (or use a *correctly escaped* `#`) they will instead be treated as aliases, and a directory
+lookup will be used to resolve their corresponding IDs.
+
+**Note**: Don't use unescaped `#` for the channel aliases as that will be treated as the `fragment` part of the URL.
+Either omit them or URL encode them, I.E. `rooms=%23alias:server` or `rooms=alias:server`
+
+### TLS
+
+If you do not have TLS enabled on the server you can disable it by providing `disableTLS=yes`. This will effectively
+use `http` intead of `https` for the API calls.