Basic

Paragraphs

Paragraphs in Markdown are just one or more lines of consecutive text followed by one or more blank lines.

On July 2, an alien mothership entered Earth's orbit and deployed several dozen saucer-shaped "destroyer" spacecraft, each 15 miles (24 km) wide.

On July 3, the Black Knights, a squadron of Marine Corps F/A-18 Hornets, participated in an assault on a destroyer near the city of Los Angeles.

Headings

You can create a heading by adding one or more # symbols before your heading text. The number of # you use will determine the size of the heading.

# The largest heading (an <h1> tag)
## The second largest heading (an <h2> tag)
...
###### The 6th largest heading (an <h6> tag)

Blockquotes

In the words of Abraham Lincoln:
> Pardon my french

Styling text

You can make text bold or italic

*This text will be italic*
**This text will be bold**

Both bold and italic can use either a * or an _ around the text for styling. This allows yo to combine both bold and italic if needed.

**Everyone _must_ attend the meeting at 5 o'clock today**

Lists

Unordered lists

You can make an unordered list by preceding list items with either a * or a -

* Item
* Item
* Item

- Item
- Item
- Item

Ordered lists

You can make an ordered list by preceding list items with a number

1. Item 1
2. Item 2
3. Item 3

Nested lists

You can create nested lists by indenting list items by two spaces.

1. Item 1
  1. A corollary to the above item.
  2. Yet another point to consider.
2. Item 2
  * A corollary that does not need to be ordered.
    * This is indented four spaces, because it's two spaces further than the item above.
    * You might want to consider making a new list.
3. Item 3

Code formating

Inline formats

Use single backticks (`) to format text in a special monospace format. Everything within the backticks appear as-is, with no other special formatting.

Here's an idea: why don't we take `SuperiorProject` and turn it into `**Reasonable**Project`.

Multiple lines

You can use triple backticks(```) to format text as its down distinct block

Links

You can create an inline link by wrapping text in brackets([]), and then wrapping the link in parentheses(())

For example, to created a hyperlink to www.danidai.com, with a link text that says, Visit DaniDai.com!, you'd write this in Markdown: [Visit Danidai.com!](http://www.danidai.com).

GitHub Flavored Markdown

GitHub uses "GitHub Flavored Markdown", or GFM, across GitHub -- in issues, comments, and pull requests. It differs from standard Markdown (SM) in a few significant ways, and adds some additinal functionality.

Differences from traditional Markdown

Multiple underscores in words

Where Markdown transforms underscores (_) in to italics, GFM ignores underscores in words, like this:

wow_great_stuff

do_this_and_do_that_and_another_thing.

This allows code and names with multiple underscores to render properly. To emphasize a portion of a work, use asterisks(`*).

URL autolinking

GFM will autolink standard URLs, so if you want to link to a URL(instead of setting link text), you can simply enter the URL and it will be turned into a link to that URL.

http://example.com

becomes

http://example.com

Strikethrough

GFM adds syntax to create strikethrough text, which is missing from standard Markdown.

~~Mistaken text.~~

becomes

~~Mistaken text.~~

Fenced code blocks

Standard Markdown converts text with four spaces at the beginning of each line into a code block; GFM also supports fenced blocks. Just wrap your code in ``` (as shown below) and you won't need to indent it by four spaces. Note that although fenced code blocks don't have to be preceded by a blank line—unlike indented code blocks—we recommend placing a blank line before them to make the raw Markdown easier to read.

Here's an example:

```
function test() {
  console.log("notice the blank line before this function?");
}
```

Keep in mind that, within lists, you must indent non-fenced code blocks eight spaces to render them properly.

Syntax highlighting

Code blocks can be taken a step further by adding syntax highlighting. In your fenced block, add an optional language identifier and we'll run it through syntax highlighting. For example, to syntax highlight Ruby code:

```ruby
require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html
```

require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html

GitHub use Linguist to perform language detection and syntax highlighting. You can find out which keywords are valid by perusing the languages YAML file.

References

1. https://help.github.com/articles/markdown-basics
2. https://help.github.com/articles/github-flavored-markdown/
3. https://help.github.com/articles/writing-on-github/