Fix config files + reorganize types

[k-tten]

Files added/modified

• .prettierrc.json - Contributors now will all have the same format
• .gitignore - Ignore dist
• .npmignore - Prevent npm from publishing useless files like src/ and tsconfig.json for smaller bundle sizes

Deleted index.js and typings.d.ts

Moved types from typings.d.ts to src/types.ts, and changed imports in files to accommodate this*

Ran prettier --write . to ensure consistent formatting

[tippfehlr]

I can't say anything about the other changes but add

  "semi": false,
  "comma": "es5",
  "singleQuote": true

to the prettier config to match existing code