Update dependencies

[StaloneLab]

This is a retake on @arobase-che's previous work on updating dependencies for zmarkdown packages.

List of changed behaviours

Here's a list of what has changed (and hence, what needs to be tested on zds-site) for reference, made by looking at the modified snapshots and fixtures:

• a blank line now separate blockquotes (solves #307);
• use \footnote instead of list of links for references in LaTeX;
• empty code spans do not render anything anymore;
• KaTeX SVG has the xmlns attribute (solves one half of #345);
• lists with empty items render a list instead of nothing;
• tables now take precedence over code blocks;
• footnotes are wrapped into a paragraph when outside a list;
• footnotes are not anymore wrapped into a paragraph when part of a list;
• footnotes order has changed (see below);
• generally, paragraphs are not added inside lists anymore;
• hl_lines and linenostart parameters for code blocks are back again for LaTeX only (solves one half #255 and #340);
• captions now break lists (this was expected by a test, which was incorrect before);
• quite a lot of changes are expected from KaTeX, please report any issue found;
• by the way, KaTeX was updated to version 0.11.1, so please update KaTeX also on zds-site (to 0.11.1) when deploying this version of zmarkdown.

What remains?

First of all, I would like a global approval of the changes above by @artragis . Maybe a review is needed (poke @vhf ), but I honestly don't know how this PR could be checked, maybe by looking at the updated tests. Most importantly, it would have been great to do a rebase, but this is very complicated to do correctly here, so I think it will be a simple merge. Finally, dependencies of remark-image-download were NOT updated, because they would need huge refactoring of the code, and I prefer to merge this first before attempting to do it (changes are less urgent, because they don't concern security issues nor are they feature-related).

[StaloneLab]

Now with rebase, please check but I think it is okay; I had to do a commit because some snapshots were still in their old version after the rebase.

[artragis]

captions now break lists (this was expected by a test, which was incorrect before);

can you explain this, And why not openning an issue that will be closed by this PR so that we can track the change?

by the way, KaTeX was updated to version 0.11.1, so please update KaTeX also on zds-site (to 0.11.1) when deploying this version of zmarkdown.

Having a look at https://github.com/KaTeX/KaTeX/releases, I see

Fix \sqrt SVG path

so @Situphen we will clearly need to update katex dependency on zds-site side

[StaloneLab]

can you explain this, And why not openning an issue that will be closed by this PR so that we can track the change?

Please refer to this test. The new behaviour is expected, not a bug, but could maybe be update if it doesn't suit zds-site needs.

so @Situphen we will clearly need to update katex dependency on zds-site side

Yes.

[vhf]

captions now break lists (this was expected by a test, which was incorrect before);

can you explain this

This used to generate a single quote:

> Foo

> Bar

Now that it generates two quotes, this should be two quotes and their respective captions:

> Foo
Source: foo

> Bar
Source: foo

Same goes for:

> * Foo
Source: foo

> * Bar
Source: foo

[artragis]

Ok so everything seems to be fine for me.