Fix JavaScript syntax highlighting on GitHub

[david-szabo97]

Changes proposed in this Pull Request

• JavaScript file syntax highlighting is broken (example https://github.com/Automattic/wp-calypso/blob/trunk/client/devdocs/index.js) on GitHub because we are trying to force them to use JSX language. This has been removed from Linguist (used by GitHub). Now it's merged into JavaScript so we don't need to specify this anymore.

Related Linguist PR: github-linguist/linguist#5133

Testing instructions

• Open https://github.com/Automattic/wp-calypso/blob/fix/github-javascript-syntax-highlighting/client/devdocs/index.js
• Force reload the page (SHIFT + CMD + R on Mac)

[matticbot]

Link to Calypso live: https://calypso.live?image=registry.a8c.com/calypso/app:build-7623
Link to Jetpack Cloud live: https://calypso.live?image=registry.a8c.com/calypso/app:build-7623&env=jetpack

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[jsnajdr]

Works well, thanks for fixing this 👍

I don't think we can test this without merging it.

For a moment, I was able to see the fixed highlighting by viewing the *.js file from the PR branch:

https://github.com/Automattic/wp-calypso/blob/fix/github-javascript-syntax-highlighting/client/devdocs/index.js

But a minute later the highlighting was broken (i.e., no highlighting) again 🤷‍♂️

For reference: the .gitattributes attribute was originally added by @sirreal in #28459.

[sirreal]

Thanks!

[david-szabo97]

For a moment, I was able to see the fixed highlighting by viewing the *.js file from the PR branch:

Actually, that worked for me after doing a force refresh. Probably it's related to some caching. But I can test this PR using this way, so just updated the PR description.

[tyxla]

Thanks for this @david-szabo97!