Make Release Notes/Known Issues available from Help in Menu Bar

[smk78]

A comment by @butler on another ticket highlighted the relative obscurity of the Known Issues.

This could be partly redressed by making the Release Notes accessible from the Help in the Menu Bar.

[smk78]

In the Ticket1176 branch I have created a new Help menu option called 'Release notes'. Selecting this brings up a popup window which specifies where the Release Notes (which incorporate Known Issues) can be found.

I'm going to issue a PR for the branch since it at least does something right now. However the 'vision' I had for the popup was that it would also display the text of the README.txt file in \sasview\installers, but sadly accomplishing that is beyond my abilities.

HOWEVER, in the process I made two observations which should be addressed before the 4.2 Release (and so I am changing the milestone of this ticket to 4.2.0):

1. We do not, as far as my searches can tell, actually bundle the README.txt with the installer downloads! Is this correct? I think we should. Else why do we bother to edit the file!

2. There is a slightly iffy looking 'Current Known Issues' bit at the bottom of ​https://github.com/SasView/sasview/releases/ which perhaps needs reviewing.

[smk78]

On the call today it was agreed to:

• do away with \sasview\installers\README-next-release.txt
• move \sasview\installers\README.txt (the detailed release notes) to \sasview\docs\sphinx-docs\user
• convert README.txt to RELEASE.rst
• do away with the popup Release Notes box created yesterday and instead just link Release Notes in the Help menu to a new documentation page \sasview\doc\user\RELEASE.html autobuilt with the documentation

All this is now done in Ticket 1176 branch.

[smk78]

Ticket1176 branch tested, approved and merged.

[richardh]

In master the new docs look good, have suggested to Steve to add a menu item in the docs to the release notes (as the release notes link to main docs but not vice versa).

If I now build docs in ESS_GUI branch, the docs do not work properly, the navigation panel on the left shuts downs, and I don't get the "allow blocked content". Suspect changes here need to be merged onto ESS_GUI?

[smk78]

Have pushed a tweak that adds a link to the release notes to index.html to address @richardh's first comment. Available in Build 414.