feat: add readme for polywrap-msgpack

Author: Niraj-Kamdar

packages/polywrap-msgpack/README.md

@@ -0,0 +1,41 @@
+# polywrap-msgpack
+
+Python implementation of the WRAP MsgPack encoding standard.
+
+## Usage
+
+### Encoding-Decoding Native types and objects
+
+```python
+from polywrap_msgpack import msgpack_decode, msgpack_encode
+
+dictionary = {
+  "foo": 5,
+  "bar": [True, False],
+  "baz": {
+    "prop": "value"
+  }
+}
+
+encoded = msgpack_encode(dictionary)
+decoded = msgpack_decode(encoded)
+
+assert dictionary == decoded
+```
+
+### Encoding-Decoding Extension types
+
+```python
+from polywrap_msgpack import msgpack_decode, msgpack_encode, GenericMap
+
+counter: GenericMap[str, int] = GenericMap({
+  "a": 3,
+  "b": 2,
+  "c": 5
+})
+
+encoded = msgpack_encode(counter)
+decoded = msgpack_decode(encoded)
+
+assert counter == decoded
+```