Clarify meaning of POPULATE_DATABASE flag

[shikasta-net]

I am unclear from the description what POPULATE_DATABASE is for. The documentation says "defaults to "True". Does the DB has to be populated or is it an existing one". I'm guessing true means the DB is populated, but I don't know why, or what with.

[meonkeys]

I read it like: "should I populate the database (True), or not (False)? I'm with you though: I'm not sure of its intended use.

And why does this setting exist at all? Wallabag itself could easily determine if it needs to create or update the schema and seed data.