[Keyboard] Add posey_split v4/v5 (#23258)

* Created posey_split keyboards and included default keymaps.

* Update keyboards/pmk/posey_split/posey_split_v4/config.h

Co-authored-by: jack <0x6a73@protonmail.com>

* Update keyboards/pmk/posey_split/posey_split_v4/config.h

Co-authored-by: jack <0x6a73@protonmail.com>

* Update keyboards/pmk/posey_split/posey_split_v4/info.json

Co-authored-by: jack <0x6a73@protonmail.com>

* Update keyboards/pmk/posey_split/posey_split_v4/info.json

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/posey_split_v4/info.json

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/posey_split_v4/readme.md

Co-authored-by: jack <0x6a73@protonmail.com>

* Various cleanup updates per QMK maintainers on PR #23258

* removed config files from via keymaps

* removed additional keyboard for PR.

* changed folder structure per PR suggestion

* Update keyboards/pmk/posey_split/v5/info.json

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v5/rules.mk

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v4/rules.mk

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v5/keymaps/VIA/keymap.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v5/keymaps/default/keymap.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v4/keymaps/default/keymap.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v4/keymaps/VIA/keymap.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v5/readme.md

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v4/readme.md

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v4/info.json

Co-authored-by: Joel Challis <git@zvecr.com>

* changed via folders to lowercase

* cleaned up extra via files in wrong folder

* Added better descriptions to keyboard projects and added hardware listing to v5

* Cleaned up keymap format

* removed extra rules

* Update keyboards/pmk/posey_split/v4/keymaps/via/keymap.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/pmk/posey_split/v5/readme.md

Co-authored-by: Joel Challis <git@zvecr.com>

* removed "about" from readme on v4

* Removed title from readme

---------

Co-authored-by: joliverMI <qmk@Desktop2023>
Co-authored-by: jack <0x6a73@protonmail.com>
Co-authored-by: Joel Challis <git@zvecr.com>

keyboards/pmk/posey_split/v4/keymaps/via/rules.mk

@@ -0,0 +1 @@
+VIA_ENABLE = yes