v10.0.0: Native TypeScript

This is a major release due to the migration to TypeScript. While technically it shouldn't change anything, it might be a breaking change in certain situations. Theres also a bugfix for watchFn and a fix for legacy browsers.

• Migrate to TypeScript [@Khartir and @phryneas in #105]
• Fix stale props being passed to promiseFn when using watchFn [@salolivares in #181]
• Avoid extending built-in JS classes [@ghengeveld in #175]
• Fix generix type declaration [@Khartir in #229]

Thanks to @Avi98, @FredKSchott and @rokoroku for reviewing and helping out.