Simplify the website hierarchy

[lehnberg]

As the website continues to evolve, our navigation and site hierarchy begins to become cluttered and filled with sections and pages. Would be good to do a comprehensive review of this.

Current

Looking at the current* website hierarchy, we have:

TOP NAV / HAMBURGER
- home
- get started
- download
- community
- friends of grin
- general fund
- research
- github

FOOTER

Left side:
- whitepapers
- security repo
- grin.mw

Right side:
- forum
- gitter
- newsletter
- twitter
- github

* this includes the proposed community section as per https://github.com/mimblewimble/site/pull/171

New proposal

HIGH LEVEL:
- home
- download
- contribute
- community
- governance
- funding

EXPANDED:
(not sub-menu items, but content and links on the pages)
 
- home
   |_ intro
   |_ get started
   |_ donate now
- download
- contribute
   |_ how to begin contributing
   |_ docs
   |_ help wanted issues in grin and grin-wallet
   |_ open research problems
- community
   |_ keybase
   |_ forum
   |_ mailing list
   |_ newsletter
   |_ code of conduct
   |_ other communities
- governance
   |_ core / council
   |_ node-dev team
   |_ wallet-dev team
   |_ moderation team
   |_ ecosystem team
- funding
   |_ addresses
   |_ general fund
   |_ friends of grin
   |_ financials

FOOTER

Left side:
- documentation
- security repo
- grin.mw

Right side:
- forum
- keybase
- newsletter
- twitter
- github

[lehnberg]

@quentinlesceller @nijynot what do you think about sth like this? perhaps you have some other ideas or proposals?

[nijynot]

@lehnberg Much better structure in the new proposal. :+1:

Maybe we should add an additional page under community, called e.g. Other communities that lists the Discord and Telegram channels?

[lehnberg]

Nice suggestion @nijynot - added other communities to community and also moved the CoC to that section :+1: