Moves keyboard shortcuts back to extra_keys docs

Author: AXVin

docs/termux/customisation/extra_keys.md

@@ -1,4 +1,51 @@
-hero: Adding Extra Keys on the touch keyboard
+hero: Various Keyboard Shortcuts for Termux and Adding Extra Keys on the touch keyboard
+
+## Understanding Keys on Termux and Shortcuts
+You might have noticed that the keyboard at the bottom of the screen has some pretty useful keys by default!
+These are `ESC`, `TAB`, `CTRL`, `ALT`, `-`, `DOWN` and `UP`.
+
+But you can always edit these if you want to!
+
+Use of keys like `ALT`, `CTRL`, `ESC` is necessary for working with a CLI terminal.
+Termux touch keyboards do not include one.
+For that purpose Termux uses the Volume down button to emulate the `CTRL` key.
+For example, pressing `VOLUME DOWN+L` on a touch keyboard sends the same input
+as pressing Ctrl+L on a hardware keyboard.
+
+The result of using `CTRL` in combination with a key depends on which program is used, but for many command line tools the following shortcuts works:
+
+* `CTRL+A` → Move cursor to the beginning of line
+* `CTRL+C` → Abort (send SIGINT to) current process
+* `CTRL+D` → Logout of a terminal session
+* `CTRL+E` → Move cursor to the end of line
+* `CTRL+K` → Delete from cursor to the end of line
+* `CTRL+L` → Clear the terminal
+* `CTRL+Z` → Suspend (send SIGTSTP to) current process
+* `CTRL+ALT+C` → Open new session (only work in Hacker's Keyboard)
+
+The Volume up key also serves as a special key to produce certain input:
+
+* `VOLUME UP+E` → Escape key
+* `VOLUME UP+T` → Tab key
+* `VOLUME UP+1` → F1 (and Volume Up+2 → F2, etc)
+* `VOLUME UP+0` → F10
+* `VOLUME UP+B` → Alt+B, back a word when using readline
+* `VOLUME UP+F` → Alt+F, forward a word when using readline
+* `VOLUME UP+X` → Alt+X
+* `VOLUME UP+W` → Up arrow key
+* `VOLUME UP+A` → Left arrow key
+* `VOLUME UP+S` → Down arrow key
+* `VOLUME UP+D` → Right arrow key
+* `VOLUME UP+L` → | (the pipe character)
+* `VOLUME UP+H` → ~ (the tilde character)
+* `VOLUME UP+U` → _ (underscore)
+* `VOLUME UP+P` → Page Up
+* `VOLUME UP+N` → Page Down
+* `VOLUME UP+.` → Ctrl+\ (SIGQUIT)
+* `VOLUME UP+V` → Show the volume control
+* `VOLUME UP+Q` → Show extra keys view
+* `VOLUME UP+K` → Another variant to toggle extra keys view
+
 
 ## Adding extra keys
 

docs/termux/customisation/index.md

@@ -81,8 +81,8 @@ and if it does; then just opens it
         ![Termux Opened termux.properties File](/images/termux_opened_properties_file.jpg)
 
 ## Adding configurations
-* [Termux Shortcuts](./keyboard_shortcuts.md)
-* [Adding Extra Keys](./extra_keys.md)
+* [Termux Shortcuts](./extra_keys.md#understanding-keys-on-termux-and-shortcuts)
+* [Adding Extra Keys](./extra_keys.md#adding-extra-keys)
 
 
 <!-- Footnotes -->

docs/termux/customisation/keyboard_shortcuts.md

@@ -24,7 +24,6 @@ nav:
         - Installation: termux/installation.md
         - Customisation:
             - Introduction: termux/customisation/index.md
-            - Keyboard Shortcuts: termux/customisation/keyboard_shortcuts.md
             - Extra Keys: termux/customisation/extra_keys.md
         # - Python: termux/python.md
     - Help & Support: support.md