Migrate `helix` common configuration (#25433)

* Initial tidying up of top level helix/ directory

Align readme.md with template & provide more detailed PCB information
Remove unused rules.mk
Add common config.h file
Update glcdfont.c with formatting and license header

* Further migrations after PRs merged

Move shared configuration to top level info.json and config.h
More descriptive hardware compatibility

* Add changelog

* Align configuration between PCBs

- Migrate beta & pico to use RGB Matrix
- Move previously RGB Matrix-dependent OLED code in rev3/rev3.c to top level
- Remove reundant OLED code in beta/beta.c
- Remove RGBLight references

* Update changelog with RGB Matrix configuration

1 files changed, 37 insertions, 0 deletions

diff --git a/docs/ChangeLog/20250831/HelixRefactor.md b/docs/ChangeLog/20250831/HelixRefactor.md
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+# Refactor of `keyboards/helix`
+
+This series of PRs aims to align this keyboard's configuration with current standards, and also remove unnecessary contents.
+
+### Refactor `helix/pico` [#25428](https://github.com/qmk/qmk_firmware/pull/25428)
+    - Removes redundant `back`, `base`, `sc`, `under`, & `qmk_conf` revisions
+    - Migrates legacy defines and configuration to JSON
+    - Migrates `default` keymap to JSON
+    - Fixes RGB configuration to illuminate 25 LEDs per half
+    - Enables standard features like Bootmagic, extrakey, etc.
+    - Updates keyboard aliases accordingly
+
+### Refactor `helix/rev2` [#25429](https://github.com/qmk/qmk_firmware/pull/25429)
+    - Removes redundant `back`, `base`, `sc`, `under`, & `qmk_conf` revisions
+    - Renames `rev2` to `beta`, as the only PCB sources in the official Helix GitHub repository are named "[beta](https://github.com/MakotoKurauchi/helix/tree/master/PCB/beta)", this keyboard's name in QMK Firmware was already "beta", and this PCB is sold under the name "[beta](https://shop.yushakobo.jp/products/oss_pcb?variant=39452554231969)" on the Yushakobo store
+    - Migrates legacy defines and configuration to JSON
+    - Migrates `default` keymap to JSON
+    - Fixes RGB configuration to illuminate 32 LEDs per half
+    - Enables standard features like Bootmagic, extrakey, etc.
+    - Updates keyboard aliases accordingly
+    - Tidy's up OLED code
+    - Adds alternate 4 row layout, as this PCB allows users to snap off the bottom row
+
+### Refactor `helix/rev3_{4,5}rows` [#25430](https://github.com/qmk/qmk_firmware/pull/25430)
+    - The `rev3_4rows` and `rev3_5rows` firmwares are identical, except for the extra row users can snap off. The 4 row PCB is not sold anywhere as an individual product, only the [5 row PCB](https://shop.yushakobo.jp/products/2143). Thus, this PR removes the aforementioned two build targets and adds a single `rev3` revision
+    - Migrates legacy defines and configuration to JSON
+    - Migrates `default` keymap to JSON
+    - Removes RGB Light configuration
+    - Updates keyboard aliases accordingly
+    - Tidy's up OLED code
+    - Adds alternate 4 row layout, as this PCB allows users to snap off the bottom row
+
+### Migrate helix common configuration [#25433](https://github.com/qmk/qmk_firmware/pull/25433)
+    - Migrates common configuration shared between revisions to the top-level keyboard directory
+    - Improves `readme.md` to provide more detail regarding PCB revisions
+    - Removes unnecessary top-level `rules.mk` file and other general tidying
+    - Migrates `beta` and `pico` revisions to use RGB Matrix, which is more appropriate as these PCBs are fit with per-key RGB LEDs