[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"
- [x] 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
Hi,
For this line, would it be better to say?
`You can add bookmark or subscribe to a specific topic by clicking the appropriate link in the “Topic tools” menu, conveniently located near the top and bottom of a topic discussion.<br />You can also subscribe, but not add bookmark, to this one by replying to a topic and checking the “Notify me when a reply is posted” checkbox.`