use/getting_started.rst: explain four methods...

...to identify to Services.

Did this get a little too verbose? I think that this did, but I need
help making this a little less verbose and CertFP requires verbosity.
getting_started.rst: fix typos noticed by

@nyuszika7h
Merge pull request #19 from Mkaysi/services

use/getting_started.rst: explain four methods...