chore: add contribution docs for writing guides

contributing/guide.md

@@ -1,10 +1,14 @@
 ## Submitting a Guide
 
-> This page is in progress.
+First of all thank you for considering to contribute to this project. It wouldn't have been possible for us to keep it live without your contributions 🙏
 
-However, please follow the below steps:
+> Follow the steps listed below in order to add a new guide
 
-* Open an issue for the topic on you would want to write. 
-* Fork this repo
-* Create a new markdown file in the [guides directory](https://github.com/kamranahmedse/roadmap.sh/tree/master/storage/guides).
-* Open a pull request.
+* Fork this repository
+* If you haven't contributed to this project before then create your author profile
+  * Open the file [authors.json](../storage/authors.json)
+  * Put your preferred `username`
+  * Put a profile picture in [authors directory](../static/authors) with the username  
+* Create a new markdown file in the [guides directory](../storage/guides).
+* Add the meta data for this guide in [guides.json](../storage/guides.json). Please note that `fileName` and `slug` must match.
+* Open a pull request