Make offline version of GenGen

I just tried the updated GenGen and it is now fantastic! Its everything I wished it would have and I couldn't be any happier.

Currently, afaik it is a web online-only application, so if the website were to go down or if a content creator was without internet, they would not be able to use this wonderful tool.

I don't know how hard it is to make it work offline, but either way I'd be happy to have a downloadable version available on itch.io or Steam. I'd be even willing to buy it for 3$ as a customer and I'm sure other world builders out there would love to have this in their toolkit. It is tremendously useful.

[rubo77]

I included the files seedrandom.js and data.txt in index.html to create a one-pager in my branch https://github.com/rubo77/PlanetGenerator/tree/offline

Then it works by just calling locally

file:///local/path/PlanetGenerator/index.html

[rubo77]

Or you start your local webserver with server.py.

Then you can access the tool via http://localhost:8000

see #7