Fix broken numbering in Nailgun section
Fix broken numbering in Nailgun section

[Roles restrictions section]
This patch fixes numerated list and adds missing periods
at the end of bullet list items.
Original page:
https://docs.fuel-infra.org/fuel-dev/develop/nailgun/customization/roles.html#roles-restrictions

Change-Id: I4db883181a7dbf25d8d6bf80dfcf4763ce932921

stackforge/fuel-web,eayunstack/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,huntxu/fuel-web,eayunstack/fuel-web,eayunstack/fuel-web,eayunstack/fuel-web,stackforge/fuel-web,stackforge/fuel-web,SmartInfrastructures/fuel-web-dev,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web,eayunstack/fuel-web,SmartInfrastructures/fuel-web-dev,huntxu/fuel-web