add basic contributing guideline

.github/CONTRIBUTING.md

@@ -0,0 +1,28 @@
+# Contribution Guidelines
+
+## Table of Contents
+
+- [Adding to this list](#adding-to-this-list)
+- [Updating your Pull Request](#updating-your-pull-request)
+
+## Adding to this list
+
+Please ensure your pull request adheres to the following guidelines:
+
+- Search previous suggestions before making a new one, as yours may be a duplicate.
+- Make sure the list is useful before submitting. That implies it has enough content and every item has a good succinct description.
+- Make an individual pull request for each suggestion.
+- Use [title-casing](http://titlecapitalization.com) (AP style).
+- Use the following format: `[List Name](link)`
+- Link additions should be added to the bottom of the relevant category.
+- New categories or improvements to the existing categorization are welcome.
+- Check your spelling and grammar.
+- Make sure your text editor is set to remove trailing whitespace.
+- The pull request and commit should have a useful title.
+- The body of your commit message should contain a link to the repository.
+
+## Updating your Pull Request
+
+Sometimes, a maintainer of an awesome list will ask you to edit your Pull Request before it is included. This is normally due to spelling errors or because your PR didn't match the awesome-* list guidelines.
+
+[Here](https://github.com/RichardLitt/docs/blob/master/amending-a-commit-guide.md) is a write up on how to change a Pull Request, and the different ways you can do that.

README.md

@@ -308,6 +308,7 @@ A collection of awesome penetration testing resources
 
 ### Contribution
 Your contributions and suggestions are heartily♥ welcome. (✿◕‿◕)
+Please check the [Contributing Guidelines](.github/CONTRIBUTING.md) for more details.
 
 ### License