Some common markups:
*italic*
italic
**bold **
bold
#Heading 1
Heading 1
##Heading 2
Heading 2
[Link](link URL)
Link
[Image|Size](Image URL)
>block quote
blockquote
* List
- List
- List
Horizontal line:
-—
`Inline code`
Inline code
For codeblock, use a pair of 3 backticks or 4 indentation to enclose the code:
```
print ‘codeblock’
```
print 'codeblock'
Adapted from CommonMark Help Section. More information can be found on their site.