A simple style sheet to read and edit issues on github.

This messes up the top heading -- they horizontally scroll off the page on
high magnification, but issue text and the issue comment editor fit on the
page up to around 400%. It meets the 320px.

You may need to adjust font-size, letter-spacing, word-spacing and
line-height to meet your tastes. It also uses my background colors. So, you
can drop them.

You only need the lines:

div.unminimized-comment.editable-comment.comment.previewable-edit.js-comment.js-task-list-container.timeline-comment.reorderable-task-lists,
div.timeline-comment
{max-width: 20em;}

I set the max-width to 20em. You might want more or less.

I'm using Safari because it allows user style sheets, but Stylus should do
it.

Warning: Some controls on gitHub disappear from  sight when you change
background color. The upload files screen loses the control that allows you
to upload files.

Wayne