Add a guide how to manually install Funkwhale from Source
Problem
Currently our installation guides just cover the download and usage of our artifacts. Especially in case of the Frontend, this means its a build provided by us. People might have several reasons not to use our builds, though, for example custom changes or they just don't trust our build chain.
Solution
Our documentation should contain a guide on how to download the source code and build everything required to run Funkwhale. This especially includes:
- Building the Frontend
- Deploying the Backend (probably doesn't make a lot of sense since its just the source anyways?)
- Build the docker containers
Workflow
@funkwhale/documentation Do you need any more information to get this started?