docs: use local Debian packages for bare-metal deployment

The Debian packages benefit from security support and should be much easier to install for most users.

Currently all requirements of Aura Engine are packaged in Debian. Thus the virtualenv-related documentation snippets can be removed.

added 21 commits

• 31c5f72c...9afa33f0 - 20 commits from branch aura:master
• 2b6ebefd - Merge branch 'master' into 'lars-debian-deployment'

Compare with previous version

mentioned in commit c4523c24

merged

@sumpfralle That's a nice one.

mentioned in commit 0895122a