Add support for map value message types

README.md

@@ -1,4 +1,22 @@
-# TODO
+# Better Protobuf / gRPC Support for Python
+
+This project aims to provide an improved experience when using Protobuf / gRPC in a modern Python environment by making use of modern language features and generating readable, understandable code. It will not support legacy features or environments. The following are supported:
+
+- Protobuf 3 & gRPC code generation
+  - Both binary & JSON serialization is built-in
+- Python 3.7+
+  - Enums
+  - Dataclasses
+  - `async`/`await`
+  - Relative imports
+  - Mypy type checking
+
+This project is heavily inspired by, and borrows functionality from:
+
+- https://github.com/eigenein/protobuf/
+- https://github.com/vmagamedov/grpclib
+
+## TODO
 
 - [x] Fixed length fields
   - [x] Packed fixed-length
@@ -7,11 +25,12 @@
 - [x] Enums
 - [x] Repeated message fields
 - [x] Maps
-  - [ ] Maps of message fields
+  - [x] Maps of message fields
 - [ ] Support passthrough of unknown fields
 - [ ] Refs to nested types
 - [ ] Imports in proto files
 - [ ] Well-known Google types
 - [ ] JSON that isn't completely naive.
 - [ ] Async service stubs
+- [ ] Python package
 - [ ] Cleanup!