Investigate tsd implementation

[garronej]

Sometime assert<Equals<A,B>> give an error when infact it shoud work.

Like for example here:

https://github.com/codegouvfr/react-dsfr/blob/842f7b820f296553593ac68aff1e72f620f030f8/src/Alert.tsx#L98

We should be able to write assert<Equals<typeof rest, {}>>.

Investigate if https://github.com/SamVerschueren/tsd has better results.