Environment variable for running behind a proxy on a path

[dbarenholz]

Is your feature request related to a problem? Please describe.
Right now, there is no easy way to host sheetable using Docker behind a reverse proxy on a subpath.

Describe the solution you'd like
Add an environment variable, e.g. ROOT_PATH, so sheetable can run on a particular path. That way, we can host sheetable behind a reverse proxy. By setting ROOT_PATH=sheets as environment variable, it would run sheetable on localhost:8080/sheets, which would allow proxying it.

Describe alternatives you've considered
For my usecase, the alternative is to keep using syncthing to sync sheets, but missing out on a much nicer tool.

Additional context
I run a variety of stuff, (almost) all behind a reverse proxy. Suppose you have a domain cool.domain.com, then I want to run sheetable on cool.domain.com/sheets/.

[vallezw]

Alright sounds useful to implement.