scenario2map should be deprecated

[bplein]

Looks like scenario2map is not really supported, so we should remove it from the README and the support files.

See this thread: https://forums.factorio.com/viewtopic.php?f=23&t=69377&p=422321&hilit=scenario2map#p422321

I found this out by trying to figure out why my map-gen settings were being ignored by scenario2map.

[bplein]

(by the way I contributed the scenario2map code, and I have no problem with it being removed... at least we can update the readme to reflect the issues)

[bplein]

I'm working on an update to docker-entrypoint.sh that should satisfy starting up a scenario with a new map. This will replace the need for individual entry points for scenario and scenario2map. I'll share my code and if desired create a pull request if you like what I've come up with.