Feature: Read botlist tokens from env

[maybeanerd]

It would be rather convenient if BLAPI could just get all tokens from the Environment.
An Idea would be to prefix them with BLAPI_ oder BOTLIST_TOKEN
An Open question is how to map them. An Idea:
Domain name (without ending or subdomain)
Would only work if there are no duplicates with other endings or subdomains, an example would be:
BLAPI_ondiscord for bots.ondiscord.xyz