Provide best-effort links to contents in `node_modules`

[DanielRosenwasser]

In cases where an error is reported from a file in node_modules, we end up with output like the following:

packages/utils/devEnv/tsconfig.json

• error TS2694: Namespace '"/mnt/ts_downloads/_/m/theatre/node_modules/@types/estree/index"' has no exported member 'StaticBlock'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/eslint/index.d.ts#L617
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/eslint/index.d.ts#L618
• error TS2300: Duplicate identifier 'ElementType'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/hoist-non-react-statics/node_modules/@types/react/index.d.ts#L3244
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/react/index.d.ts#L3244
• error TS2300: Duplicate identifier 'LibraryManagedAttributes'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/hoist-non-react-statics/node_modules/@types/react/index.d.ts#L3254

I think it would be helpful if we could provide a link to the exact version on unpkg, or more ideally, GitHub if we could really figure that out.