Fix typos

CHANGELOG

app/assets/javascripts/notes.js

app/controllers/admin/users_controller.rb

app/controllers/projects/team_members_controller.rb

app/helpers/application_helper.rb

app/models/namespace.rb

app/models/network/graph.rb

app/models/project.rb

app/models/user.rb

app/models/wiki_page.rb

app/observers/activity_observer.rb

app/services/notification_service.rb

app/views/help/public_access.html.haml

app/views/projects/compare/show.html.haml

app/views/projects/new.html.haml

app/views/projects/wikis/_new.html.haml

doc/api/issues.md

doc/api/projects.md

doc/api/users.md

doc/make_release.md