[OTHER] Add TechStack to README.md

### I have searched through the issues and didn't find my problem.

- [X] Confirm

### What would you like to share?

Would be nice to have a `TechStack` or `Built With` section in the README, where we list the technologies, languages, tools and frameworks that are used to develop, build and maintain the repo and website.
It could also be used as sort of a showcase of the icons by adding icons for each technology.

Maybe categorizing by what they're used for would be nice too?

Anyways, here are some of the technologies I know we use, but there are probably a few more that I'm missing:
- [Devicon.dev](https://devicon.dev) (`HTML`, `CSS`, `JavaScript`, `Angular`)
- To automate processes (`GitHub Actions`, `CI/CD`, `Python`, `Selenium`, `Gulp.js`)
- Icons (`SVG` and `JSON` editing)
- Documentation (`GitHub Wiki`, `Markdown`, `HTML`, `CSS`)

### Additional information

Please come with suggestions