Draft: Resolve "Building docs independently from the python package"

Closes #1207 (closed)

The "compiled" documentation should not be part of the python source distribution. Reasoning:

• we need the nomad package to build the documentation which actually should also contain the documentation... Currently the only way to build the python sdist by building it twice.
• most of the other links on the gui are also pointing to external link
• it is more just a decimation of the usage of the gui...
• the link of the logo of the documentation redirect to a another page (central deployment) and not to the one where it was actually deployed.