14.0 web widget html markdown

[gfcapalbo]

V14 port of web_widget_html_markdown

    - change version
    -  change name of some methods of WYSIWYG.
    -  fixed bug on empty creation

rest worked out of the box.

[thomaspaulb]

NOTE: continuation of #4, see comments there also.

[thomaspaulb]

So you've basically copied a lot of code from the original HTML widget of Odoo. And we're also using it, of course, when the user switches to Html.

To avoid duplication of code, we basically have two options:

1. Don't inherit from DebouncedField, but directly from HtmlField instead and then override its workings. I remember I specifically asked you to inherit from DebouncedField and it was because I saw some stuff in the Html widget's code that looked incompatible with what we wanted to do, but that was before we decided to offer live switching between HTML and Markdown. The situation might look different now - what's your thought on this?

2. Instead of creating a new widget, we just enhance the existing HTML widget so that ALL Html fields in the system can now be edited with Markdown. Seems on one hand very useful, but also a bit radical - at least user should be able to switch off that behaviour in order to have a remedy for any bugs that our enhancements might cause in his particular incarnation of Odoo.

I'm not bothered for now but let's keep this as an open discussion point for when we polish this module for OCA.

[gfcapalbo]

code replication: We had decided that inheriting from Htmlfield was not possible, i can't remember why , but for the OCA it's worth a read to check again, remember the why of this decision, and see if v14 changes this, making it possible to fix.

[gfcapalbo]

@thomaspaulb as i implement fixes i see 2.1.0 released, a lot of activity.
there is a breaking change:

https://github.com/showdownjs/showdown/releases/tag/2.1.0

but we never use the CLI. so it should be drop-in replacement.

hopefully we will have some improvements, Looking at the log , it's mostly documentation and some lib upgrades, but i see work done in the converter too here and there.

[gfcapalbo]

@thomaspaulb update the documentation now directs us to the plugins used by kevin to improve showdown:
https://github.com/showdownjs/showdown/blob/master/docs/extensions-list.md

          showdown-footnotes.js    leave as is not updated since 2016
          showdown-toc.js    leave as is not updated since 2015
          showdown-table.js   ---> not in official list, so i should remove it, it seems unsupported. I will leave it for testing, 
                               just in case it does a decent job in converting tables, even if not officially recognized.

[gfcapalbo]

2.1 is not a release, code will still be tagged as 2.0, but it is not alpha anymore and has all the fixes.
2.1 was just a tag they used on the repo.

[gfcapalbo]

@thomaspaulb done all fixes ( except for the "copied code" one,), updated libs to latest. made a quick test. no regressions