Document how 'Cmdr:' and 'Ship:'/'Role:' changes for Private Groups and Multi-Crew.

Home.md

@@ -114,6 +114,23 @@ filled in.
 
 The user-interface is deliberately minimal - your choice of data is automatically downloaded, transmitted and/or saved when you start Elite: Dangerous, land at a station, jump to a system or scan a body. 
 
+## Commander Name
+This is the part of the UI with the label "Cmdr:".
+
+If you aren't in a Private Group, nor taking part in Multi-Crew, then
+the text to the right of the label will simply show your current Commander's
+name.
+
+If you are in a Private Group then then it will be of the form:
+`<Command Name> / <Group Name>`.  Keeping in mind that `<Group Name>`
+will simply be the name of the Commander whose Private Group you are
+currently using.
+
+If you are taking part in Multi-Crew activities on another Commander's
+ship then this will be of the form: `<Commander Name> / <Name of Commander whos ship you're in>`.
+
+You can differentiate this from the Private Group case by checking if you
+have a 'Ship:' or 'Role:' label, see below.
 
 ## Ship Name
 The text next to the label 'Ship:' will contain either the model of
@@ -126,6 +143,11 @@ provider in your web browser.
  * Change which provider you use on 'File' &gt; 'Settings' &gt;
  'Configuration' (tab) &gt; 'Preferred websites' &gt; 'Shipyard'.
 
+If you are in Multi-Crew on another Commander's ship then
+the label will change to 'Role:' and the text will be the role you're
+currently fulfilling on the ship.  You **cannot** click the text to
+access the build of the ship you're Multi-Crewing in.
+
 ## System name
 Click on the system name to view its entry on your chosen 'System'
 provider in your web browser.