:memo: Update README.md
:memo: Update README.md

- :art: Cleanup.  Typos etc.
andykog/mobx,andykog/mobservable,mweststrate/MOBservable,mobxjs/mobx,andykog/mobx,mobxjs/mobx,mweststrate/MOBservable,andykog/mobservable,mobxjs/mobx,mweststrate/MOBservable,mobxjs/mobx