feat: add contribution guide

CONTRIBUTING.md

@@ -0,0 +1,28 @@
+# Contributing Guides
+
+First of all, thank you for your effort to improve this action. This guide will help you regarding various aspects like putting issues, contributing a feature, etc.
+
+## Code of Conduct
+
+This project and everyone participating in it is governed by the [Code of Conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code. Please read the [full text](CODE_OF_CONDUCT.md) so that you can read which actions may or may not be tolerated.
+
+---
+
+## Before Submitting a Pull Request
+
+**Before submitting your pull request** make sure the following requirements are fulfilled:
+
+- Fork the repository
+- Add project from [render-dev](render-dev) folder
+- Install the recommended version of [Unity](https://unity.com/)
+- Create a branch from `develop`
+- Define consistent coding styles with [EditorConfig](render-dev/.editorconfig)
+- Change necessary code for bug fix, a new feature and format it
+- Make sure all are unit test passing
+
+## Reporting an issue
+
+Before submitting an issue, you need to make sure:
+
+- Kindly provide an adequate description and a clear title
+- If possible, share a URL towards the repository in which action is failing

README.md

@@ -4,14 +4,14 @@ NPRP is a Non-photorealistic Render Pipeline for Unity Engine. It is modeled aft
 
 > Its predecessors were some toon shaders under URP. You can get the source code [here](https://github.com/flicker-studio/NPRP/releases/tag/v0.1.0-alpha).
 
-## Contribution
-
-If you will contribute to this project, check out the [roadmap](https://github.com/orgs/flicker-studio/projects/2) and start your work. We need to make sure we are not doing the same thing.
-
 ## Install
 
 It's still under development and expected to provide in Unity Package Manager after finishing the first version.
 
+## Contribution
+
+If you will contribute to this project, check out the [roadmap](https://github.com/orgs/flicker-studio/projects/2) and [contributing guides](CONTRIBUTING.md).
+
 ## Acknowledgement
 
 ### Collaborators