Migrate remaining HTML files in org.eclipse.platform.doc.user to HMTL5

[ptziegler]

Contributes to
#3275

[akurtakov]

In book.css there is class table.border which will save you a lot of copy/paste in different files if you're interested to use it.

[ptziegler]

In book.css there is class table.border which will save you a lot of copy/paste in different files if you're interested to use it.

Thanks for the hint. That made things much cleaner 😄