chore(docs): updating readme

README.md

@@ -1,2 +1,20 @@
-# protobuf-definitions
-Protobuf definitions for function to host callbacks
+# Tarmac Protobuf Definitions
+
+This repository contains the protobuf definitions for the Tarmac project.
+
+The protobuf definitions are used by Tarmac SDKs or functions directly to perform host calls to the Tarmac server.
+Communication between the Tarmac server and functions/SDKs is via [waPC](https://wapc.io/) WebAssembly Procedure Calls.
+
+## Structure
+
+| Proto File | Description |
+|------------|-------------|
+| `tarmac.proto` | Contains common messages used for various message types. |
+| `kvstore.proto` | Protobuf definitions for KVStore related messages. |
+| `metrics.proto` | Protobuf definitions for Metrics related messages. |
+| `http.proto` | Protobuf definitions for HTTP client related messages. |
+| `sql.proto` | Protobuf definitions for SQL query related messages. |
+
+## Contributing
+
+Contributions are  welcome please open an issue or submit a pull request for any changes or improvements.