Callback that is invoked when the
Brewery is started
and allows server components to perform startup initializations
when the server is started.
When the brewery is started, the collections suppliers, ingredients
and beers will be scanned for Startables in that order.
And each collection elements are scanned in order of addition.
Brewery#start() of the brewery is done automatically
when the first component is requested from the brewery. But it's also
possible to invoke start manually.
This is different
Brewable#brew(Brewery) because that method is
called when the component is actually brewed into a beer (lazy initialization).