add guide for common matrix moderation actions

docs/guides/matrix-taking-moderation-action.md

@@ -6,7 +6,7 @@ title: "Matrix: Taking Moderation Action"
 
     Perform common moderation actions in Matrix using our moderation bot
 
-See the [Matrix-Moderation](/docs/concepts-and-configurations/matrix-moderation.md) Concept for an overview on how the moderation system functions.
+See the [Matrix-Moderation](../concepts-and-configurations/matrix-moderation.md) Concept for an overview on how the moderation system functions.
 
 All bot actions are triggered through the *CCCHH Moderation Management* room.
 
@@ -34,7 +34,7 @@ All bot actions are triggered through the *CCCHH Moderation Management* room.
 - `<reason>` should be supplied and supports quotation (`"<reason>") if more than one word is used
 - When a domain is banned, we usually also ban all subdomains too. This needs to be done in two separate commands.
 
-## Redacting Messages
+## Redacting a single Message
 
 ```
 !mjolnir redact <permalink>
@@ -42,3 +42,11 @@ All bot actions are triggered through the *CCCHH Moderation Management* room.
 
 - `<permalink>` is **not** the message ID but the actual *https://matrix.to/#blablabla* link that can be retrieved with most clients through a *Share* or *Copy link to Message* button on an individual message.
 
+## Redacting all Messages of a User
+
+```
+!mjolnir redact <user-id>
+```
+
+- `user-id` the Matrix-ID of the user of whom all messages in all rooms should be redacted (e.g. `@bla:example.com`).
+