Add TypeScript support

[dsevillamartin]

Support TypeScript

• Support forum.ts & admin.ts
• Can import TS files from JS just fine
• Babel processes TS
• Add tsconfig.json

  • Don't think all those config keys are needed, but to make code editors a bit happier when linting

  • tsconfig.json is not required in projects, but code editors will want it - its contents can just be

    {
      "extends": "flarum-webpack-config"
    }

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How do we want to add this to core?

Perhaps publish a beta 11 (I changed the version here to beta.11-dev)? That might be the easiest way.

[tankerkiller125]

Especially since it only adds typescript support and doesn't change anything else I'd say go for it.

[dsevillamartin]

We'd probably publish this as beta 11 after merging to be able to easily use in flarum/core to start converting to TS.

[askvortsov1]

@datitisev would you be comfortable merging this now and publishing so we can use it in core, and putting the core extension stuff in a second (soon to follow) release? Or do you prefer that we release both at the same time? I just feel like we need some more discussion on the other one, but this one seems good to go

[dsevillamartin]

@askvortsov1 We don't need to publish this yet. My PR has a temporary TS configuration (suggested by Franz) so that we don't have to publish this yet, specially if problems arise.

[dsevillamartin]

Switched to draft so that we remember to revisit this and make the proper changes.

[davwheat]

I'm just curious, but why do we need all the extra options compared to our existing TS shim used in core?

[davwheat]

Superseded by #11.