Markdown: add Table, Emoji and Highlight Text

• Emoji: :joy:, :+1:
• Highlight Text: ==very important==
• Table:

| abc | abc |
| --- | --- |
| abc | abc |

FEATURE: 455561

Which was not added from the extended syntax:

• Heading IDs: ### My Great Heading {#custom-id}
• Subscript: H~2~O
• Superscript: X^2^
• Definition Lists:

First Term
: This is the definition of the first term.

The rest was already done