Resolve "Style the docs"

Closes #4

See merge request inject/inject-docs!4

Resolve "Add backend as a submodule into the repo"

Closes #5

See merge request inject/inject-docs!5

Merge branch 'main' of https://gitlab.fi.muni.cz/inject/inject-docs into 5-add-backend-as-a-submodule-into-the-repo

Add test site

Closes #7

See merge request inject/inject-docs!3

Resolve "Visual style of navigation bar"

Closes #2

See merge request inject/inject-docs!2

Resolve "Initial setup"

Closes #1

See merge request inject/inject-docs!1