Add basic usage information to README

README.md

@@ -1,2 +1,32 @@
 # pfizerhash
 
+Generate pseudonyms for user profiles based on hashing of user data.
+CSV file with user data and a header is read line by line.
+Every line is converted to JSON object and hashed using the scrypt algorithm.
+A salt of at least 16 bytes must be used. 
+
+## Requirements
+
+Tested to work with Python 3.6
+
+Either Python 3.6 with OpenSSL 1.1+ or py-scrypt is required.
+
+```bash
+  pip install py-scrypt
+```
+    
+## Usage/Examples
+
+See help for more information:
+```sh
+python3 pfizerhash.py -h
+```
+  
+## Authors
+
+- [Anton Kasimov](https://gitea.radium.group/toxa)
+  
+## Refferences
+
+ - [The scrypt Password-Based Key Derivation Function](https://datatracker.ietf.org/doc/rfc7914/) (RFC 7914)
+ - [Stronger key derivation via sequentialmemory-hard functions](http://www.tarsnap.com/scrypt/scrypt.pdf) by [Colin Percival](https://en.wikipedia.org/wiki/Colin_Percival)