[Keyboard] Adds Gray Studio HB85 Initial Support (#5311)

* Gray Studio HB85 Initial Support

* Fixed README image

* Updated README

* Disabled Bootmagic and Console for HB85

* Fixed Numpad 4 matrix place

* Fixes board crashing with RGB enabled

* Moved HB85 files to gray_studio folder

* Uses old i2c library since this version makes RGB underglow work

* Improved default keymap with underglow control layer

* Removes obsolete program and uses generic script instead

As per zvecr feedback

* Uses GPIO Functions to initialise and set RGB underglow PINS

keyboards/gray_studio/hb85/readme.md

@@ -0,0 +1,60 @@
+# Gray Studio HB85
+
+![Gray Studio HB85](https://i.imgur.com/Sk3cupR.jpg)
+
+A HitBit MSX Computer inspired Keyboard.
+
+Keyboard Maintainer: [Felipe Coury](https://github.com/fcoury)  
+Hardware Supported: Gray Studio HB85  
+Hardware Availability: Group buy finished  
+
+Make example for this keyboard (after setting up your build environment):
+
+    make hb85:default
+
+See [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) then the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information.
+
+
+ps2avrGB keyboard firmware
+==========================
+
+This keyboard uses the port of the QMK firmware for boards that are based on the
+ps2avrGB firmware.
+
+Note that this is a complete replacement for the firmware, so you won't be
+using Bootmapper Client to change any keyboard settings, since not all the
+USB report options are supported.
+
+## Installing
+
+First, install the requirements. These commands are for OSX, but all you
+need is the AVR toolchain and `bootloadHID` for flashing:
+
+```
+$ brew cask install crosspack-avr
+$ brew install --HEAD https://raw.githubusercontent.com/robertgzr/homebrew-tap/master/bootloadhid.rb
+$ pip install pyusb
+```
+
+Then, with the keyboard plugged in, simply run this command from the
+`qmk_firmware` directory:
+
+```
+$ make hb85
+$ bootloadHID -r hb85_default.hex
+```
+
+## Setting the board to bootloader mode
+
+Hold the F3 key while plugging the USB cable.
+
+## Troubleshooting
+
+From my experience, it's really hard to brick these boards. But these
+tricks have been useful when it got stuck in a weird scenario.
+
+1. Try plugging the board in while holding the bootloader key. This will force
+   it to boot only the bootloader without loading the firmware. Once this is
+   done, just reflash the board with the original firmware.
+2. Sometimes USB hubs can act weird, so try connecting the board directly
+   to your computer or plugging/unplugging the USB hub.