Add Yeehaw Keyboard (#12705)

* Add files for Yeehaw keyboard.

* Modified config.h and default keymap.

* Update keyboards/yeehaw/rules.mk

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update keyboards/yeehaw/readme.md

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update keyboards/yeehaw/readme.md

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update keyboards/yeehaw/keymaps/via/keymap.c

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update keyboards/yeehaw/keymaps/via/keymap.c

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Update keyboards/yeehaw/keymaps/via/keymap.c

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Apply suggestions from georges review

Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>

* Remove Unnecessary Defines

Co-authored-by: Drashna Jaelre <drashna@live.com>

* Changed keymap licenses 📃

Co-authored-by: Tsqaushv2 <61706196+Tsqaushv2@users.noreply.github.com>
Co-authored-by: ridingqwerty <george.g.koenig@gmail.com>
Co-authored-by: Drashna Jaelre <drashna@live.com>

keyboards/yeehaw/readme.md

@@ -0,0 +1,22 @@
+# Yee-Haw Macro Pad
+
+![Yeehaw](https://imgur.com/a/P6eSrcy)
+
+A 14 key macro pad in the shape of Texas.
+
+* Keyboard Maintainer: [Caleb Lightfoot](https://github.com/Tsquash)
+* Hardware Supported: Yee-Haw PCB v1.0
+* Hardware Availability: [squashkb](https://www.squashkb.com)
+
+Make example for this keyboard (after setting up your build environment):
+
+    qmk compile -kb yeehaw -km default
+    
+To reset the keyboard, press the physical reset button located on the back of the PCB.
+
+Install example for this keyboard:
+
+    qmk flash -kb yeehaw -km default
+
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).