* Convert to using TypeScript
Next.js v.9 allows converting an existing project to TS by simply renaming the files as TS files
* Fix type errors: Type 'string' is not assignable to type 'number'.
* Add mention about missing typings for javascript-time-ago
* Add GA_INITIALIZED to window
* Fix type error in feed transformers
* Model MembershipInfoForm state and props with TS
* Silence the typescript warning in MembershipInfoForm
* Add threshold to Fader props
* Fix Warning: Each child in a list should have a unique "key" prop.
Sponsors don't have ids – name is probably unique and can be used as a key
* Allow key as prop for SponsorLink
* Add type of the props for SponsorLink
