Support for `.javascript`, `.typescript`, `.jsx`, and `.tsx`

[Yash-Singh1]

Currently, these files aren't syntax highlighted.

• .typescript (Add .typescript and .javascript support #372)
• .javascript (Add .typescript and .javascript support #372)
• .jsx
• .tsx

[davidhcefx]

These are not extensions of Typescript of Javascript, according to Wikipedia. Neither did File-Extensions.org recognizes them.

• https://en.wikipedia.org/wiki/JavaScript
• https://en.wikipedia.org/wiki/TypeScript

[Yash-Singh1]

However, many people use that file extension.

[davidhcefx]

Merged to galenguyer/nano-syntax-highlighting in galenguyer#3