Added info.json for mt980 keyboard and fixes to walker keymap (#5391)

Added info.json for mt980 keyboard and fixes to walker keymap (#5391)

* Added info.json and minor fixes to walker keymap

* Fix url

* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Update keyboards/mt980/info.json

Co-Authored-By: walkerstop <walkerstop@gmail.com>
* Fix user calling keymap functions

* cancel oneshot layer on KC_TRNS

* Fix to oneshot layer handling

* Fix oneshot handling of reset

* Move bootmagic key to Esc where it normally resides

* Remove deprecated function

* Treat shift-numlock as shift-insert in Walker layer