added the shortcut for 'm' & '-'

Author: WilcoSp

docs/content/2.guide/2.keyboard-shortcuts.md

@@ -29,8 +29,10 @@ These shortcuts work anywhere on the site. Press `/` from any page to quickly se
 
 ## Package page
 
-| Key | Action           |
-| --- | ---------------- |
-| `.` | Open code viewer |
-| `d` | Open docs        |
-| `c` | Compare package  |
+| Key | Action            |
+| --- | ----------------- |
+| `m` | main package      |
+| `.` | Open code viewer  |
+| `d` | Open docs         |
+| `c` | Compare package   |
+| `-` | Changelog package |