[Keyboard] Add CSTC40 rev3 (#25285)

* refactor cstc40, add rev3 fxtwink variant

* cleanup readmes

* readme nitpick

* add cstc40 aliases

* format-json

* add communty_layouts per code review

* touch copied legacy files for newline

* fix LED flags

* update readme files per code review

data/mappings/keyboard_aliases.hjson

@@ -1860,6 +1860,12 @@
     "kin80": {
         "target": "kin80/blackpill401"
     },
+    "kprepublic/cstc40/daughterboard": {
+        "target": "kprepublic/cstc40/rev1"
+    },
+    "kprepublic/cstc40/single_pcb": {
+        "target": "kprepublic/cstc40/rev2"
+    },
     "kumaokobo/kudox_full": {
         "target": "kumaokobo/kudox_full/rev1"
     },