Add support for the DURGOD Taurus K320 keyboard (#11399)

* Initial support for Durgod K320 with BootMagic Lite

- Adding missing files
- Add Unicode Map Support & new user keymap
- Remove personalized features from Default keymap
- Added Unicode Map to both Default and kuenhlee keymap.c
- Updated readme.md
- Added additional Fn Shortcut keys

* Additional support for Durgod K320

- Simplifying default keymap
- Renaming durgod_k320 => durgod/k320
- Removing copy of ST_NUCLEO64_F070RB from K320. Replacing with local board.h
- Adding Mac keyboard layout for K320 as alternative via Fn+F12
- Implementing Windows Key lock on K320
- Cleaning up duplicated core functionality
- Adding default_toggle_mac_windows keymap with:
  - Ability to toggle between Windows and MacOS layout
  - Mac Media Lock functionality.

* Updating K320 keymap readme

Co-authored-by: kuenhlee <eos.camera.lee@gmail.com>

keyboards/durgod/k320/keymaps/default_toggle_mac_windows/readme.md

@@ -0,0 +1,64 @@
+# A keymap for Durgod Taurus K320 that supports toggling between Mac and Windows
+
+Layer 0 : Standard ANSI 87 Keys TKL layout (Windows)
+
+Layer 1 : Media control and Windows lock key (Windows)
+- Reusing Durgod's Original Media Control for Fn + F1 ~ Fn + F7
+- Fn + Windows to toggle Windows lock key functionality
+
+Layer 2 : System layer (Windows)
+- Fn + Menu + Esc : Bootloader mode
+- Fn + Menu + F1  : System Sleep
+- Fn + Menu + F4  : Turning Off System
+- Fn + Menu + F12 : Switch to Mac layout
+
+Layer 3 : Mac 87 Keys TKL layout
+
+Layer 4 : Media control and Media lock key (Mac)
+ - Standard Mac Media keys for Fn + F1 ~ Fn + F12.
+ - Fn + F13 to toggle Media lock key functionality
+
+Layer 5 : System layer (Mac)
+- Fn + R-ALT + Esc : Bootloader mode
+- Fn + R-ALT + F4  : Shutdown/Sleep (Hold down on Mac)
+- Fn + R-ALT + F12 : Switch to Windows layout
+
+## Toggle between Mac and Windows layout
+
+You can switch between Mac and Windows layout by doing the following:
+- Hold down Fn + Menu (Windows Layout) or Fn + Right-Alt (Mac layout)  (These are the same physical keys)
+- Press F12
+
+The 'M' led will be lit when you are using the alternate layout.  By default Mac is the alternate layout.
+
+You can change the default & alternate layout by setting the following flags to either '_WBL'(Windows) or '_MBL' (Mac)
+- DEFAULT_LAYOUT (initial layout to use on boot)
+- ALT_LAYOUT (layout that will light the 'M' LED when active)
+
+For example, to configure Mac as the default layer, and Windows to be the alternate layout, compile with these flags:
+
+    make EXTRAFLAGS="-DDEFAULT_LAYOUT=_MBL -DALT_LAYOUT=_WBL" durgod/k320:default_toggle_mac_windows
+
+## Windows key lock
+
+In windows layout, you can hold down Fn + Windows key to disable the Windows key while in locked mode.  The 'Lock' LED
+indicates if the Windows key is locked.
+
+This is similar to the stock K320 Windows key lock functionality.
+
+## Mac Media Lock
+
+To switch between Function row and Media row in Mac layout, press Fn + PrtSc.  The 'Lock' LED indicator will be lit when in Media row mode.
+
+### Subsequent Flashing
+
+For repeating Flashing you have two options with this keymap:
+1. Use BootMagic
+- BootMagic Lite has been enabled with Assigned "Esc" key 
+- Unplug USB Cable
+- Holding Esc Button 
+- Plug in USB Cable, Keyboard should be in ST-Bootloader state
+2. Use key combination if using default keymap
+- Hold down Fn + Menu (Windows Layout) or Fn + Right-Alt (Mac layout)  (These are the same physical keys)
+- Press Esc.  Keyboard should go into booloader state.
+