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/bootloader_defs.h

@@ -0,0 +1,7 @@
+/* Address for jumping to bootloader on STM32 chips. */
+/* It is chip dependent, the correct number can be looked up here (page 175):
+ * http://www.st.com/web/en/resource/technical/document/application_note/CD00167594.pdf
+ * This also requires a patch to chibios:
+ *  <tmk_dir>/tmk_core/tool/chibios/ch-bootloader-jump.patch
+ */
+#define STM32_BOOTLOADER_ADDRESS 0x1FFFC800