Add a section in docs for projects/repos that are using Njord

[mjovanc]

This is to showcase other peoples project. Take inspiration from this: https://github.com/rust-unofficial/awesome-rust

[Hiccup-za]

@mjovanc Do you want this section to be within the documentation itself or high-level in a markdown file like the example?

[mjovanc]

@Hiccup-za I don't know what will look best. I will give you the freedom to choose that :)