At101ish (#25072)

* Dell AT101 replacement pcb support

* Update keyboards/at101ish/readme.md

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* remove empty src clause in makefile

* feature: Update at101ish to qmk v0.28

* feature: Add osdetecting keymap variant.

* refactor: Move at101ish keyboard to handwired folder.

* fix: Adjust at101ish readme-

* fix: review changes.

* chore: Remove unneeded feature.

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Co-authored-by: fauxpark <fauxpark@gmail.com>

Author: henrikosorensen