Document external tools better in the user manual: VS Code / Eclipse / brew etc.

[TimLethbridge]

Add one or more user manual pages covering

• How to use the VS Code plugin
• How to use the Eclipse plugin
• How to use the Sublime text plugin
• How to use brew with umple (and when complete apt, chocolatey etc.)

There is already a general 'Umple Tools' manual page that should link to this/these, or that page could be enhanced