Updating docs for Toolbar and Tools

[originalfoo]

Just a personal checklist for ongoing work on docs; already got all the info I need, just need to clean stuff up a lot.

First batch:

• Parking restrictions: Image
• Parking restrictions: See also
• Parking AI
• Speeds: See also ⏸
• Vehicle restrictions: Images
• Vehicle restrictions: Notes - check links, etc
• Vehicle restrictions: FAQ
• Vehicle restrictions: See also
• Junction restrictions: Overview
• Junction restrictions: Notes about Policies settings
• Junction restrictions: Images
• Junction restrictions: Shortcuts?
• Junction restrictions: Icons
• Junction restrictions: See also
• Lane arrows: Shrink Overview
• Lane arrows: Overlays - on the roads!
• Lane arrows: Apply -> Customise
• Lane arrows: Note on bus policies
• Lane arrwos: See also
• Lane connectors: Everything
• Priority signs: Refactor
• Priority signs: Shorcuts
• Traffic lights: Everything