Exclude node_modules and minified files from search tools like `rg` and `ag`.

- Use system fonts only for text to avoid FOUT
- Move font-awesome to npm/webpack
- Move NotoColorEmoji to web_src
- Remove presumably unneccesary 'PT Sans Narrow'
- Simplify webpack import exclusions

Fixes: https://github.com/go-gitea/gitea/issues/11818
Fixes: https://github.com/go-gitea/gitea/pull/11814

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>

promises are polyfilled by babel, it's no longer needed.

* Add .ignore file for search tools

Tools like `rg` [1] and `ag` [2] support a `.ignore` file which defines
files that are ignored during a recursive search. This adds the file
which makes recursive file searches in the code base ignore files that
are generally not desirable to search in like bindata, vendored files
and compiled frontend assets.

[1] https://github.com/BurntSushi/ripgrep/
[2] https://github.com/ggreer/the_silver_searcher

* add leading slash

* remove files already in .gitignore