In the previously built UNICADO website, many pages had inconsistent
headers. This commit aims to address the issue by leveraging mkdoxy
documentation. Initially, only propulsion_design-related files have been
modified to test this approach. If successful, the solution can be
extended to all other subpages to resolve the header inconsistency
problem.
Issue: #22

# Conflicts:
#   .gitlab-ci.yml
#   docs/get-involved/developer-installation.md
#   mkdocs.yml

Fix incorrect path to logo

See merge request !15

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

Merge branch 'documentation/webpage-content' of git.rwth-aachen.de:unicado/unicado.gitlab.io into documentation/webpage-content

This commit partially addresses the issue Integrate mkdoxy in pipeline.
Creates mkdoxy documentation for files inside Aircraft Design repository.
This also link generated documentation to the UNICADO website.
Following files are editted:
1. .gitlab-ci.yml : clone aircraft-design and libraries repo
2. scripts/copy_aircraft_design_to_docs.py ( Copy aircraft-design to
   docs folder of gitlabio repo.
3. overrides/main.html :Adapted to disply footer logo on all pages
4.  mkdocs.yml : Changed link to documentation.

Issue: #21

added codeowners file as part of Issue UNICADO/Unicado-Package #6

See merge request !14