Added contribution secction to the readme

CONTRIBUTING.md

@@ -0,0 +1,27 @@
+# Contributing
+
+1. Sign one of the contributor license agreements below.
+1. [Install Go](https://golang.org/doc/install).
+1. Clone the repo:
+
+   `git clone https://github.com/dubyte/dir2opds.git`
+
+1. Change into the checked out source:
+
+   `cd dir2opds`
+
+1. Fork the repo.
+1. Set your fork as a remote:
+
+   `git remote add fork https://github.com/GITHUB_USERNAME/dir2opds.git`
+
+1. Make changes and commit
+   to your fork. Initial commit messages should follow the
+   [Conventional Commits](https://www.conventionalcommits.org/) style (e.g.
+   `feat(functions): add gophers codelab`).
+1. Send a pull request with your changes.
+1. A maintainer will review the pull request and make comments. Prefer adding
+   additional commits over amending and force-pushing since it can be difficult
+   to follow code reviews when the commit history changes.
+
+   Commits will be squashed when they're merged.

README.md

@@ -66,3 +66,6 @@ ExecStart=/home/pi/dir2opds/dir2opds -dir <FULL PATH OF BOOKS FOLDER> -port 8080
 [Install]
 WantedBy=multi-user.target
 ```
+
+# How to contribute
+  - [Contributing](CONTRIBUTING.md)