feat: added basic readme

README.md

+# Adaptive Huffman
+
+## Usage
+
+### Encoding
+
+```bash
+python3 dyn_huffman.py -e "darkvador"
+```
+
+### Decoding
+
+```bash
+python3 dyn_huffman.py -d "000011 0 000000 00 01101 100 00110 1100 10001 10 0 11100 01010 110"
+```