Markdown syntaxe are slitly different depending on what platform your using it. For instance Github use it's own variation of Markdown-here, which itself is a variant of Markdown.

You need 3 white-spaces before the character to indent (tab in) a list item.

* Item 1
   * Item 1.a
      * Item 1.a.1
   * Item 1.b
* Item 2

• Item 1
  • Item 1.a
    • Item 1.a.1
  • Item 1.b
• Item 2

You paste the same «1. » at EVERY LINES. The rendring engine will apply the proper number to each items.

1. Item 1
   1. Item 1.a
      1. Item 1.a.1
   1. Item 1.b
1. Item 2

1. Item 1
   1. Item 1.a
      1. Item 1.a.1
   2. Item 1.b
2. Item 2

Markdown do allow some basic HTML tags like the <h4> in the following example.

thead/tr1/th1 | thead/tr1/th2
:---: | ---
tbody/tr1/td1 | tbody/tr1/td2
`:---:` <h4>Center aligned</h4> 050 bytes lôrem ïpsum dolor encore cinquante bytes | `---` <h4>Left aligned within `<tbody>` only</h4> 050 bytes lôrem ïpsum dolor encore cinquante bytes
tbody/tr3/td1 | tbody/tr3/td2
tbody/tr4/td1 | tbody/tr4/td2

• Embed YouTube videos in Markdown File
• Mastering Github Markdown : A guide specifically for Github's syntaxe.
• Markdown Syntax : John Gruber's document is a major reference.
• Awesome Markdown : A collection of awesome markdown goodies (libraries, services, editors, tools, cheatsheets, etc.) by Adam Pritchard.
• Markdown Cheatsheet by Adam Pritchard.

• Markdown PDF : Node module that converts Markdown files to PDFs.
• Typora.io : An open sourced Markdown editor standalone software supported on Linux, Mac & Windows. Read more : Typora.io Tips and Tricks.
• Mardown-Here Live Demo