add discord badge, change links, add copyright notice

added discord badge
changed all discord links to the vanity link
changed links to various community sites, left links same changed the title of hyperlinks
added copyright notice

Merge pull request dappnode#454 from dappnode/pablo/deprecate-openeth…

…ereum

Deprecate openethereum

Merge pull request dappnode#416 from dappnode/update-profile

update core packages versions

Merge pull request dappnode#415 from dappnode/update-profile

update core packages versions

Merge pull request dappnode#404 from dappnode/update-profile

update core packages versions

fix typo

fix typo

fix typo

fix typo

Merge pull request dappnode#341 from dappnode/pablo/commands-refactor

commands refactor && update debian ISO image