[Docs] Add Encoder requirements to PR Checklist doc (#17634)

Co-authored-by: Nick Brassel <nick@tzarc.org>

docs/pr_checklist.md

@@ -79,6 +79,9 @@ https://github.com/qmk/qmk_firmware/pulls?q=is%3Apr+is%3Aclosed+label%3Akeyboard
     - `matrix_init_board()` etc. migrated to `keyboard_pre_init_kb()`, see: [keyboard_pre_init*](custom_quantum_functions.md?id=keyboard_pre_init_-function-documentation)
     - prefer `CUSTOM_MATRIX = lite` if custom matrix used, allows for standard debounce, see [custom matrix 'lite'](custom_matrix.md?id=lite)
     - prefer LED indicator [Configuration Options](feature_led_indicators.md?id=configuration-options) to custom `led_update_*()` implementations where possible
+    - Encoder support should not be hacked into the keymap here -- no `tap_code(dynamic_keymap_get_keycode())` or `action_exec()` hacks.  The [Encoder Map](feature_encoders.md?id=encoder-map) feature already supports the dynamic keymap feature (what power's VIA's "live keymap updates" capability).
+      - If support is absolutely necessary, it should be implemented exclusively at the keymap level, with none of the implementation bleeding into the keyboard level (no empty rows/columns, no encoder specific layouts, etc.), as those configurations can be redefined at the keymap level. Keymaps can then choose to use the `action_exec` hack. <!-- because people will complain, give them a way to implement it, in the meanwhile.  To be removed. -->
+      - [Request for official proper VIA support](https://github.com/the-via/app/issues/26)
 - `<keyboard>.h`
     - `#include "quantum.h"` appears at the top
     - `LAYOUT` macros should use standard definitions if applicable