Adding upstream version 0.8.9.

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

docs/services/slack.md

@@ -0,0 +1,36 @@
+# Slack
+
+!!! attention "New URL format"
+    The URL format for Slack has been changed to allow for API- as well as webhook tokens.  
+    Using the old format (`slack://xxxx/yyyy/zzzz`) will still work as before and will automatically be upgraded to
+    the new format when used.
+
+The Slack notification service uses either [Slack Webhooks](https://api.slack.com/messaging/webhooks) or the 
+[Bot API](https://api.slack.com/methods/chat.postMessage) to send messages.  
+
+See the [guides](../guides/slack/index.md) for information on how to get your *token* and *channel*.
+
+
+## URL Format
+
+!!! note ""
+    Note that the token uses a prefix to determine the type, usually either `hook` (for webhooks) or `xoxb` (for bot API).
+
+--8<-- "docs/services/slack/config.md"
+
+!!! info "Color format"
+    The format for the `Color` prop follows the [slack docs](https://api.slack.com/reference/messaging/attachments#fields)
+    but `#` needs to be escaped as `%23` when passed in a URL.  
+    So <span style="background:#ff8000;width:.9em;height:.9em;display:inline-block;vertical-align:middle"></span><code>#ff8000</code> would be `%23ff8000` etc.
+
+## Examples
+
+!!! example "Bot API"
+    ```uri
+    slack://xoxb:123456789012-1234567890123-4mt0t4l1YL3g1T5L4cK70k3N@C001CH4NN3L?color=good&title=Great+News&icon=man-scientist&botname=Shoutrrrbot
+    ```
+    
+!!! example "Webhook"
+    ```uri
+    slack://hook:WNA3PBYV6-F20DUQND3RQ-Webc4MAvoacrpPakR8phF0zi@webhook?color=good&title=Great+News&icon=man-scientist&botname=Shoutrrrbot
+    ```