Add initial description of xrestrict usage

This change includes an initial brief blurb about invoking xrestrict, and links to the project page. As I write more documentation I will either include it here or on the project page as appropriate.
Merge pull request #1 from Ademan/patch-1

Add initial description of xrestrict usage
Wrap xrestrict utility section
Update tablets to fix huion-driver links
Add more details on drivers
Remove trailing space from the drivers page source
Remove "index.html" from URLs in page issue template
Move maillist info to the end of support page
Add Huion H610 monoprice rebranding
Add tools to devel page.
Update usbhid-dump latest release
Add converted tablet diagnostics collection HOWTO
howto: diag: Lower header levels
howto: diag: Fix terminal example formatting
howto: diag: Remove usbhid-dump links
howto: diag: Fix example tablet link
howto: diag: Embed videos
howto: diag: Refine introduction and disclaimer
support: Remove redundant "HOWTOs" from headers
Update UC-Logic TWHA60 info