ExAd/CONTRIBUTING.md

#Contribution Guidelines Please ensure your pull request adheres to the following guidelines:

• Search previous suggestions before making a new one, as yours may be a duplicate.
• Suggested READMEs should be beautiful or stand out in some way.
• Make an individual pull request for each suggestion.
• New categories, or improvements to the existing categorization are welcome.
• Keep descriptions short and simple, but descriptive.
• Start the description with a capital and end with a full stop/period.
• Check your spelling and grammar.
• Make sure your text editor is set to remove trailing whitespace.

Thank you for your suggestions!