Added type definitions for react-remarkable

[hotzenklotz]

I added type definitions for the react-remarkable package. Unfortunately, there were not @types/react-remarkable definitions available to I had to write my own.

Steps to test:

• Run type checker
• CI should be enough

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(Please delete unneeded items, merge only when none are left open)

• Updated changelog
• Updated migration guide if applicable
• Updated documentation if applicable
• Adapted wk-libs python client if relevant API parts change
• Removed dev-only changes like prints and application.conf edits
• Considered common edge cases
• Needs datastore update after deployment

[MichaelBuessemeyer]

Thanks for adding the type and improving the typing 🙏

I only found one minor thing, regarding the defined type.
If you disagree with me there, feel free to merge this pr without the small suggestion :)