Add Generic Keymap for my boards (#2795)

* add mechmerlin 60 ansi layout

* put meaningful #defines

* missed the backslash

* add merlin split layout

* rename to have a -ansi

* Add appropriate readme files

* rename KEYMAP to LAYOUT

* support for default layout

* support for the community keymaps

* make sure I don't break the configurator

* Don't break the configurator Merlin

layouts/community/60_ansi_split_bs_rshift/mechmerlin-split/readme.md

@@ -0,0 +1,17 @@
+MechMerlin's Split ANSI 60% Layout
+======================
+
+This is the 60% layout with split backspace and right shift used by u/merlin36, 
+host of the [MechMerlin](www.youtube.com/mechmerlin) YouTube channel.
+
+It is used on his   
+[Sentraq S60-X RGB](https://github.com/qmk/qmk_firmware/tree/master/keyboards/s60_x)   
+[MechanicalKeyboards.com FaceW](https://github.com/qmk/qmk_firmware/tree/master/keyboards/bfake)   
+
+## Keymap Notes
+- Highly influenced by the KBP V60 and WKL B.Face standard layouts
+- Does not support any form of inswitch or underglow lighting as Merlin hates them.
+- Arrow toggle switch is the 1u key by right shift
+
+### Build
+To build this keymap, simply run `make your_keyboard:mechmerlin-split`.