Inconsistencies in Markdown block when compared to GitHub

[Andre601]

There are currently a few inconsistencies for displaying the Markdown content in Blocks vs how it is rendered by GitHub itself.

This issue should help listing these inconsistencies.
Be aware that those are only the ones I so far have found. There may be more...

I found the issues while looking at the README.md for one of my repositories (Andre601/AdvancedServerList) through blocks.githubnext.com

1. <img> display ignores width/height and also has weird spacing

<img> tags used in the README don't have their height attributes ignored, making the SVG in my case default to its default sizing.

Additionally are the images themself separated into individual lines with huge spaces, while on GitHub they display next to each other (As I intended).

Screenshots:

• Blocks:
  
• GitHub:
  

2. Reference Links are not linking (While still being highlighted)

Links using the Reference link format ([text][link_name]) don't actually make an embedded link. Instead is the text highlighted in blue, while the [link_name] is shown at the end (Also highlighted).

Screenshots:

• Blocks:
  
• GitHub:
  

3. Tables are not rendered

Tables aren't rendered at all.

Screenshots:

• Blocks:
  
• GitHub: