docs: update Compatibility section with new names and links (#315)
docs: update Compatibility section with new names and links (#315)

- `rollup-plugin-` -> `@rollup/plugin-`
  - just less confusion for newer users who may not be aware of the
    previous naming. and up-to-date / current naming anyway

- clarify grammar in `@rollup/plugin-babel` to be a bit more specific
  - remove part about what "it claims", no need for negative tone
- add a link to the Babel plugin's docs for its default extensions
- comment out ellipsis in code samples (closer to valid code)
ezolenko/rollup-plugin-typescript2,ezolenko/rollup-plugin-typescript2