Provide example for backend parameters
Provide example for backend parameters

Update the design about cluster parameters and provide
some example of backend parameters. By now this includes
all supported parameters.

Reviewed-by: iustinp, ultrotter


leshchevds/ganeti,mbakke/ganeti,leshchevds/ganeti,onponomarev/ganeti,yiannist/ganeti,bitemyapp/ganeti,ganeti/ganeti,bitemyapp/ganeti,leshchevds/ganeti,grnet/snf-ganeti,mbakke/ganeti,andir/ganeti,yiannist/ganeti,apyrgio/ganeti,apyrgio/snf-ganeti,apyrgio/snf-ganeti,dimara/ganeti,dimara/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,grnet/snf-ganeti,andir/ganeti,ganeti/ganeti,onponomarev/ganeti,apyrgio/ganeti,andir/ganeti,mbakke/ganeti,ganeti/ganeti,ganeti-github-testing/ganeti-test-1