Update documentation: offline voting, forum usage, environment variables

[abourget]

The way environment variables are interpreted is not clear from using the binary alone.

We need an Examples section, or a few Getting Started tutorials:

• Forum usage
• Offline tx signing
• Multisig flows

[joshkauffman]

Offline signing has been added to eosc.app under Getting Started - https://eosc.app/getting-started/offline/
Forum hugo template is created and needs content added - https://github.com/eoscanada/eosc/blob/gh-pages-hugo/docs/content/en/getting-started/forum-overview.md
Msig huge template is created and needs content added -
https://github.com/eoscanada/eosc/blob/gh-pages-hugo/docs/content/en/getting-started/msig-overview.md

[joshkauffman]

Once we have the other docs created, we can figure out the best way to display them. Either in a new 'Tutorials' section, maybe a subheader to 'Getting Started', etc.
I think @avionrouge will have some good ideas/know the limitations of hugo. He's fought it the hardest :)