initial commit: gd-controls plugin scaffolding

- promptfont font assets and license
- key_mapping CSVs for Godot input bindings and prompt-font glyphs
  across keyboard/mouse, PC/Xbox/Sony/Nintendo controllers, and touch
- gen.py generates prompt_font_mapping.gd from key_mapping/promptfont.csv,
  splicing between STARTGEN/ENDGEN markers
- device, manager, file_manager scaffolding (work in progress)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,16 @@
+# macOS
+.DS_Store
+
+# Godot 4+
+.godot/
+.import/
+export.cfg
+export_presets.cfg
+
+# Imported translations (autogenerated from CSVs)
+*.translation
+
+# Mono
+.mono/
+data_*/
+mono_crash.*.json