[WIP] Add TypeScript declaration files to output

[EdricChan03]

This PR introduces declaration files to the output. The changes include:

1. Adding a TSConfig override in the Bili config to allow for declaration files to be generated and are then generated in ./dist/types.
2. Adding the necessary JSON properties to package.json such that the TS compiler can detect the declaration files (as indicated in the TypeScript docs for publishing declaration files).

Caveats

The typings currently don't include the community notations.

Additional notes

• Could the notations be potentially used on their own in the future?
• I've fixed an issue in src/community/infix-abstract.ts which broke the build
• Here's a preview of what the output would be:

Closes #150

[dan-simon]

Is this PR also mergeable?

[EdricChan03]

Is this PR also mergeable?

I've not (yet) tested if the typings are actually usable. Additionally, community notation typings are also generated but won't work if the community notations aren't actually imported so this may require a general restructure of how community notations would be consumed