Improved rake documentation for importing existing repositories with a rake task.
Added the satellites:create step, that might be necessary after the import.
Corrected syntax.
Corrected the wording of the documentation and the layout.
Corrected layout, to be more friendly.
Fixed typo
Modified according to suggestions by @sytse
Merge branch 'improve_rake_import_doc' into 'master'

Improve import Documentation

Improved the documentation steps for importing bare git repositories to GitLab.

@dzaporozhets I added a step to create gitlab-satellites. Is this step really necessary, or do the satellites get created as needed?

See merge request !1234