refactor: migrate most JS to TS, migrate to Docusaurus v3, MDX v3

Description

Upgrade to Docusaurus v3 and MDX v3 which enabled a lot of refactorings and lintings but introduced many breaking changes to v1/v2.
Refactored most of JS code to TS
Introduced more static checks
Cleaned up dependencies

[x] ✨ improve(docs) - e.g. added a new paragraph, example, using a better wording, adding a new document, etc.
[x] 🛠️ fix(docs) - bug fix, e.g. fix a typo, page render issue
[x] ❌ BREAKING CHANGE(docs) - e.g. removing a document/article/category that was referenced in many other places
[x] 🧹 refactor(docs) - changed a code example, e.g. replaced old code with a modern one
[ ] 🗑️ chore(docs) - other changes that don't affect the docs, e.g. updating the CI/CD pipeline

[x] ✨ feat(platform) - a new feature, e.g. a new MDX component, plugin, theme, etc.
[x] 🛠️ fix(platform) - bug fix, e.g. fix a typo, issue causing component to crash
[x] ❌ BREAKING CHANGE(platform) - e.g. removing a feature, changing the API, etc.
[x] 🧹 refactor(platform) - code improvements, changes, e.g. unifying style, renaming internals, etc.
[x] 📝 docs(platform) - updated code documentation
[x] 🗑️ chore(platform) - other changes that don't affect the platform directly, e.g. updating the CI/CD pipeline