Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1 +1,40 @@
-##
+# Contributing Guide
+
+Contributors can add new useful functions to the foss42 core library or new data (check `foss42/data/`) by following the below steps:
+
+**Step 1**: Raise a new issue that you want to add new function/data. We will assign the issue to you and label it.  
+**Step 2**: Star and fork THIS repository.  
+**Step 3**: Now in your fork, make the required changes.  
+**Step 4**: Raise a PR with your changes.  
+**Step 5**: Wait for review and PR merge.  
+
+## Setting up Dev env
+
+- Install the latest version of Python.  
+- Clone the repo to your local sytem.  
+- Use terminal to navigate inside the repo.  
+- Execute `pip3 install -e .` to install the library locally.  
+- Now you can import and use the library in the local enviroment.
+
+```python
+>>> import foss42.text.humanize as hz
+>>> hz.humanize_bytes(1126,
+                      2,
+                      prefix = True,
+                      trailing_zeros = True)
+>>> '1.10 kilobytes'
+```
+
+## Testing
+
+Install `pytest` via the following command
+
+```
+$ pip3 install pytest
+```
+
+Now inside the folder, run the tests using the command:
+
+```
+$ pytest
+```