Add TypeScript about scratch-js

[yashprit]

@richgilbank if its still open or nobody is working, can I work on this?

[richgilbank]

@yashprit Please do! Nobody's working on it to my knowledge. http://www.typescriptlang.org/Playground Might be a good starting point (doesn't look like there are any additional network requests made once the page is loaded). If you have any questions about how to add it, feel free to ask.

[richgilbank]

@yashprit Have you had a chance to take a crack at this yet?

[yashprit]

@richgilbank I still need to start it, I have got some time this week, let's crack it.

[aluanhaddad]

@richgilbank Cool project! The reason no errors are being reported is because you have not set reportDiagnostics: true. This will cause the compiler to populate the diagnosticsproperty ofresult`.

See my comment on #84