Add Contributing Guide

Author: ua-nick

Diff for: CONTRIBUTING.md

@@ -0,0 +1,20 @@
+# Contributing Guide
+
+Hi! Thanks for the interest in the project. Here are some notes if you want to make the project better ;)
+
+#### I have a question
+Clearly formulate your question and create an issue.
+
+#### I have found a bug
+Simply create a pull request and provide a detailed description of the problem.
+
+#### I have a proposition for improvement
+Create an issue if you have an idea or create a pull request if you know how to solve it in a source code.
+
+#### I have made own implementation of algorithm or data structure
+Unfortunately, we do not accept third-party implementations.
+
+### General notes
+- Make your code clean and clear.
+- Make sure that your code passes the tests, otherwise, it will be rejected.
+- Use labels to specify the type of issue or pull request.

Diff for: README.md

@@ -49,7 +49,7 @@ Don't forget about proverb:
 
 ## Contribute
 
-We would be happy to receive your propositions of improvement ;)
+We would be happy to receive your propositions of improvement! Read [Contributing Guide](https://github.com/floyernick/Data-Structures-and-Algorithms/blob/master/CONTRIBUTING.md) for more details.
 
 ## License