For a main heading us a single #

This is main heading (h1)

For a sub heading use a double ##

This is a sub heading (h2)

Just type normally for a paragraph.

This is a paragraph.

For bold use ** at the start and end of the bolded section.

This is bold

For italic use _ at the start and end of the italicized section.

This is italic

For strikethrough use ~~striked 1~~

For a smile emoji type 😄 without the space between the colons

This is an emoji 😄

Horizontal rule --- doesn't see to work so I used <hr></hr>

For a blockquote use "> blockquote"

blockquote

1. This is an ordered list.
2. This is 2nd item on the list.
3. This is the third item.