[WIP] syntax highlight at search bar

[asukaminato0721]

maybe possible:

https://codemirror.net/

and

https://github.com/codemirror/lang-rust

[asukaminato0721]

@hkmatsumoto can't find the frontend code.

[hkmatsumoto]

Here is the repo. Due to the constraints of the hosting service, it belongs to my personal account.

[hkmatsumoto]

Currently, react-syntax-highlighter is used to color rust codes in documentation, so it is a good idea first to try using that.