Markdown support: Code blocks about web-components

[K-Kumar-01]

@jeromesimeon @irmerk
Did some work to add the feature.
Here is a recording.
https://www.loom.com/share/238dbd1abb1e4a159038d113c61860aa

Is this feature correct?
Let me know if there are any changes required.

some things to note:

1. the icon used is similar to the code icon
2. Shortcut key does not work currently

[K-Kumar-01]

@jeromesimeon @irmerk
Requesting your review

[irmerk]

Should this support start in markdown-transform @jeromesimeon?

[jeromesimeon]

Should this support start in markdown-transform @jeromesimeon?

We already support code blocks in the markdown-transform

The video looks nice. Sadly the bottom of the screen doesn't show the markdown for that part of the document (I don't think?) so it's difficult to say if what's in the editor gets properly translated to a markdown block.

@K-Kumar-01 This looks great. If you have another video, or maybe even better a PR we could evaluate your proposal better!

[irmerk]

Use #289 as reference when starting this.