TypeScript declarations

[deanylev]

Any plans to add TypeScript declarations? Was surprised to find no issues about this. Happy to take a crack at it myself

[mkszepp]

@deanylev not directly planned but we need it too.. if you find any time feel free to convert to TS or adding declarations

[LucasHillDex]

Typescript definitions would be very helpful for using w/ GTS template tags which is the way most ember apps are going