Add `postinstall` script recommendation in readme

[karlhorky]

Hi, thanks for this project, really cool!

What are your thoughts on using typesync in a postinstall script? So that @types packages are installed automatically?

If https://github.com/jeffijoe/typesync/issues/46 gets implemented with "removing unused types", then it may be a good idea to recommend postinstall-postinstall for users of Yarn.

[jeffijoe]

46 should be possible now with the --ignorepackages option

[karlhorky]

Ok, and about the postinstall idea? Have any thoughts?

[jeffijoe]

I haven't tried it so I can't speak for it. I have heard, though, that postinstall are a can of worms.

[karlhorky]

Hm, ok. To be clear, I mean just adding this line to the package.json:

{
  "scripts": {
+    "postinstall": "typesync"
  }
}

This would cause the typesync command to be automatically run after each npm install or yarn add. Example in npm docs.

[jeffijoe]

Sure. You can add it as a recommendation to the readme.

[karlhorky]

Maybe the recommended postinstall should actually be typesync && npm install (or typesync && yarn), because of what @aequasi mentioned: https://github.com/jeffijoe/typesync/issues/44#issuecomment-768928750

[karlhorky]

Ok, opened #65 for this