update to montex code

[vinorodrigues]

Hey there,

I've updated the code a bit - more aligned with the recent 0.17.0 release. Changes are (in summary):

• remove VIA_QMK_RGBLIGHT_ENABLE - in 0.17.0 this will actually cause a compile error as is.
• more data driven config - moved things like matrix, debounce, usb id's etc, to the config.json file as the QMK admins push to "data driven" configuration
• simple copyright headers - using short notation for copyright headers
• readme image on imgur - for some reason the QMK admins are insisting the product images be hosted on imgur
• some code cleanup

If you just merge this into yours then the QMK PR will also have it. Once done I can then get on discord and encourage them to relook and merge it.