Update documentation

Author: kishaningithub

README.md

@@ -1,2 +1,44 @@
 # setup-python-amazon-linux
-Github action to install python in all flavours of amazon linux
+
+Github action to install python in all flavours of amazon linux. The goal of this action is to be a drop in replacement 
+for the github's official [setup-python action](https://github.com/actions/setup-python) to the maximum extent possible.
+
+## Why?
+
+- This project exist because as of Nov 2023 [Github has no plans support amazon linux](https://github.com/actions/setup-python/issues/460#issuecomment-1185723652) for its official 
+[setup-python](https://github.com/actions/setup-python) action for amazon linux self hosted runners.
+
+## Implementation caveat
+
+This action compiles the desired version of python from source for the first time because the glibc version in use in 
+amazon linux 2 is very old (2.26) and the pre-made existing binary distributions fail with the following error
+
+```yaml
+python: /lib64/libc.so.6: version `GLIBC_2.27' not found
+python: /lib64/libc.so.6: version `GLIBC_2.28' not found
+```
+
+Hence only for the first time this action may like 3 to 4 minutes depending on the runner configuration. Post this only cache
+will be used and hence will be very fast (4 to 5 seconds)
+
+## Supported amazon linux flavours
+
+- Amazon Linux 2
+- Amazon Linux 2023 
+
+If you need support for more kindly raise an issue or a PR
+
+## Usage
+
+All you have to do is change "setup-python" to "setup-python-amazon-linux" in your workflows
+
+```yaml
+steps:
+- uses: actions/checkout@v3
+- uses: actions/setup-python-amazon-linux@v1
+  with:
+    python-version: '3.10' 
+- run: python my_script.py
+```
+
+For more options to the action, kindly refer [action.yml](./action.yml)