[Keyboard] Tmo50 initial commit (#4891)

* Create ISO HHKB keymapping for GH60

* Add media controls to Fn layer

* Use M(x) instead of F(x), add Copyright text

* Create initial firmware for TMO50

* Correct year and author

* Fix repos README

* Remove unnecessary code

* Change include guard in tmo50.h

keyboards/tmo50/readme.md

@@ -0,0 +1,15 @@
+# tmo50
+
+![tmo50](https://imgur.com/BhRYzl6.jpg)
+
+TMO50 is a 50% mechanical keyboard with macro column on the left side. Sub60% board without compromises.
+
+Keyboard Maintainer: [funderburker](https://github.com/emiilsd)  
+Hardware Supported: TMO50 mechanical keyboard  
+Hardware Availability: Group buys  
+
+Make example for this keyboard (after setting up your build environment):
+
+    make tmo50: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).