[Keymap] Planck Keymap: Inkwell (#14311)

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

keyboards/planck/keymaps/inkwell/readme.md

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+# The Inkwell Planck Layout
+
+*/
+Plank keymap with Base, Lower, Raise, and Adjust layers, and 1 encoder.
+
+Features:
+- Number Pad
+- Symbol Pad
+- Function Pad
+- Programming utilities: ()[]{}<>
+- Mouse Control
+- Encoder:
+  - Volume (default turn)
+  - Brightness (shift+turn)
+  - Scroll Y(RSE+turn)
+  - Scroll X (RSE+shift+turn)
+  - Zoom (push+turn)
+  - Play/Pause (double click)
+/*