This is preparation for enabling an eslint indentation configuration.
90% of these changes are just fixes for indentation errors that have
snuck into the codebase over the years; the others are more
significant reformatting to make eslint happy (that are not otherwise
actually improvements).
The one area that we do not attempt to work on here is the
"switch/case" indentation.
In HTML, the line break immediately following a start tag is ignored
(see: https://www.w3.org/TR/html4/appendix/notes.html#h-B.3.1). An
extra span tag has been introduced in the upstream Pygments
HtmlFormatter in order to preserve the first new line. The Bugdown
Tests as well as our fenced_code.js frontend markdown processor have
been updated to reflect this new behavior.
See #2357. We now support `~~~ .py ` with that trailing space.
Note that the test coverage is Python-side only due to
bugdown_matches_marked being set to false, since we don't yet
support language syntax on the client side.
(imported from commit ccd5fcb0eee01478d349161400103480678d7486)