Added type definition for notyf

[gurov]

Please fill in this template.

• [v] Use a meaningful title for the pull request. Include the name of the package modified.
• [v] Test the change in your own code. (Compile and run.)
• [v] Follow the advice from the readme.
• [v] Avoid common mistakes.
• [v] Run npm run lint package-name (or tsc if no tslint.json is present).

Select one of these and delete the others:

If adding a new definition:

• [v] The package does not provide its own types, and you can not add them.
• [v] If this is for an NPM package, match the name. If not, do not conflict with the name of an NPM package.
• [v] Create it with dts-gen --dt, not by basing it on an existing project.
• [v] tslint.json should be present, and tsconfig.json should have noImplicitAny, noImplicitThis, strictNullChecks, and strictFunctionTypes set to true.

[dt-bot]

types/notyf/index.d.ts

Checklist

• is correct naming convention?
  • https://www.npmjs.com/package/notyf - https://github.com/caroso1222/notyf#readme
• has a test file? (notyf-tests.ts or notyf-tests.tsx)

[DanielRosenwasser]

Thank you!