Clean up 1.1.0 release notes

[matthewhelmke]

This PR:

• Adds a menu entry for the new release version notes to the main Releases page
• Adjusts the title of the 1.0.0 release notes in the left hand menu to conform to the pattern of the other release notes
• Makes some edits to the 1.1.0 release notes, just to clean them up a little
• Changes the title of the section in the table of contents from "Releases" to the more-accurate "Release notes"
• Fixes the name of the initial release from 1.0 to the more-accurate 0.1.0, including changing the filename and links.