Remove refinerycms-i18n from edge template because it will be required by core.
Update "Custom View/Layout" guide to reflect latest changes in master.

Refinery::Pages.use_view_templates and
Refinery::Pages.view_template_whitelist was recently removed.
Merge pull request #2340 from refinery/update_custom_views_and_templates_guide

Update "Custom View/Layout" guide to reflect latest changes in master.

[ci skip]
Remove outdated guides.

[ci skip]
Merge pull request #2342 from refinery/remove_outdated_guides

Remove outdated guides.
Remove redundant </p> tag in translation guide.

[ci skip]
Merge branch 'master' of https://github.com/refinery/refinerycms