[ticket/13041] Help_faq.php language file needs to be revised

Todo:
- [x] Reodering "login and registration issues"
- [x] Updating "login and registration issues"
- [x] Updating "User Preferences and settings" 
- [x] Updating "Posting Issues"
- [x] Updating "Formatting and Topic Types"
- [x] Updating "User Levels and Groups"
- [x] Updating "Private Messaging"
- [x] Updating "Friends and Foes"
- [x] Updating "Searching the Forums"
- [ ] Updating "Topic Subscriptions and Bookmarks"
- [x] Updating "Attachments"
- [x] Updating "phpBB3 Issues"
- [ ] Adjust/correct some answers to be compliant with new phpBB features

This is a WIP PR.
To be discuss.

PHPBB3-13041
I would omit `and ask them for their reasons`. I don't think we should compel people to ask admins for the reasons to why they set up the board the way they did. We should just end it by suggesting they can contact their admin.