Radio controls guidebook entry (#13990)

* Added radio guidebook entry with channel designators

* Radio guidebook update

* Update Resources/Server Info/Guidebook/Controls/Radio.xml

Oh yeah, I definitely can see where a change to the radio_channels.yml would cause a desync here. I will need to look into how to link the xml to Resources\Prototypes\radio_channels.yml

Co-authored-by: Kara <lunarautomaton6@gmail.com>

* Delete .gitignore

Woops, how'd that get in there?

* Revert "Delete .gitignore"

This reverts commit 54a92b65b4cbbb39e6d162ab02cbe875ca5210d5.

* Update .gitignore

* Update .gitignore

* Update Controls.xml

* Update Controls.xml

* Less hard coded hotkey information

* Cleaned up old text

* Update .gitignore

* Update Radio.xml

---------

Co-authored-by: Kara <lunarautomaton6@gmail.com>

Resources/Server Info/Guidebook/Controls/Controls.xml

@@ -1,4 +1,4 @@
-<Document>
+<Document>
 # Controls
 
 <Box Orientation="Vertical">You can change the keybinds at any time here:</Box>

Resources/Server Info/Guidebook/Controls/Radio.xml

@@ -0,0 +1,26 @@
+<Document>
+  # Radio
+
+  Your radio allows you to communicate across the entire station and to your specific [color=#a4885c]department[/color].
+
+  <Box>
+    <GuideEntityEmbed Entity="ClothingHeadsetGrey"/>
+  </Box>
+
+  To send a station-wide message over the radio preface your text with [color=#a4885c]semi-colon (;)[/color].
+
+  ## Departmental Radio
+
+  You are able to send messages over your departmental radio channels using [color=#a4885c]colon (:)[/color] followed by the
+  department letter as long as you're wearing a headset with your department's encryption key.
+
+  Examine your headset to see the department channels available to you.
+
+<Box>
+  <GuideEntityEmbed Entity="ClothingHeadsetEngineering"/>
+</Box>
+
+  Examining a default engineering headset would show you the prefixes for the [color=#32cd32]Common[/color] and [color=#f37746]Engineering[/color]
+  channels.
+
+</Document>