fix minor spelling mistakes

Merged username-removed-490101 requested to merge realsobek/gitlab-ee:master into master

See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html

What does this MR do?

It fixes minor spelling mistakes.
Solves gitlab-org/gitlab-ce#37921

I used the browser to make the changes, hence I could not create a changelog entry and squash the commits.
@axil The 'assign to' field is missing in the 'merge request' form. I hope pinging is OK.

Moving docs to a new location?

no

See the guidelines: http://docs.gitlab.com/ce/development/doc_styleguide.html#changing-document-location

  • Make sure the old link is not removed and has its contents replaced with a link to the new location.
  • Make sure internal links pointing to the document in question are not broken.
  • Search and replace any links referring to old docs in GitLab Rails app, specifically under the app/views/ directory.
  • If working on CE, submit an MR to EE with the changes as well.