.md file | README.md

• Human readable - Human can read and understand easily.
• Plain text - Human readable text with no additional functionality like bold, italic, etc.
• Rich text - Style text or formatted text.  
• Markup language - Plain text document with syntax. Create rich text using plain text syntax.
• Lightweight markup language - Markup language which is easy for human read.
• Markdown language - Lightweight markup language (web) which is easily converted to HTML. 
• MD file - Extract form Markdown language.
• MD file feature - Source code version control. use plain text (may include inline text symbols) for styling.
• MD file in GitHub - README.md is most commonly used md file. Also pull request and gits.

Most common syntax of .md file

1. Mention people - @galib
2. Heading (h1-h6)  - #Hi I am <h1> tag. ######Hi I am <h6> tag.
3. Bold - **bold*,__also bold__
4. Italic - *italic*, _italic_
5. Strikethrough - ~~strikethrough~~
6. Order list - 1.parent
1. Child
7. Unordered list - *patent *child[whit tab]
8. Emoji for md file - https://www.webpagefx.com/tools/emoji-cheat-sheet/