Revises the dashboard links to emphasize beta testing procedure.
Revises the dashboard links to emphasize beta testing procedure.

Closes flarum/core#542
- Includes a disclaimer stating that the software is provided mainly
for testing.
- Directs bug reports to the Support tag in the forums instead of the
issue tracker
- Directs feedback to the Features tag in the forums

Albert221/core,Albert221/core,malayladu/core,kirkbushell/core,flarum/core,datitisev/core,malayladu/core,kirkbushell/core,zaksoup/core,datitisev/core,renyuneyun/core,renyuneyun/core,kidaa/core,zaksoup/core,kidaa/core,renyuneyun/core,zaksoup/core,flarum/core,kidaa/core,datitisev/core,kirkbushell/core,malayladu/core,Luceos/core,Luceos/core,flarum/core,datitisev/core,Albert221/core,kirkbushell/core,Luceos/core,malayladu/core,Albert221/core,Luceos/core,renyuneyun/core