feat(i18n): set up glossary (#2198)

This pull request introduces the initial glossary for the project to
improve the translation quality.

Implements #2148.

### TODOs

- [x] Add the definition YAML
- [x] Add a generator to produce Crowdin-compatible (TBX v3) format
- [x] AGENTS.md
- [ ] ~Workflow~ (Split to another PR)
- [ ] ~Skills~ (Same as above)

cspell.config.yaml

@@ -52,6 +52,7 @@ words:
   - clippy
   - clustr
   - cmdorctrl
+  - codenames
   - codesign
   - collectblock
   - colorjs
@@ -189,6 +190,7 @@ words:
   - MeshToonMaterial
   - meteocons
   - micvad
+  - MikuMikuDance
   - mineflayer
   - mingcute
   - minimizable