Add README.md with Protobuf definitions and usage instructions for exileapi project

Author: Florin Stan

README.md

@@ -0,0 +1,50 @@
+# exileapi Protobuf Definitions
+
+This repository contains the Protobuf definitions for the exileapi project.
+
+## Buf Schema Registry
+
+These definitions are managed using [Buf](https://buf.build/). They are automatically linted, checked for breaking changes, and pushed to the [Buf Schema Registry (BSR)](https://buf.build/tcn/exileapi) via GitHub Actions.
+
+The module name is `buf.build/tcn/exileapi`.
+
+## Usage
+
+You can depend on these Protobuf definitions in your own projects using Buf. Add the following dependency to your `buf.yaml` file:
+
+```yaml
+version: v2
+deps:
+  - buf.build/tcn/exileapi
+```
+
+Then, run `buf mod update` to fetch the dependency.
+
+## Development
+
+### Linting
+
+To lint the definitions locally:
+```bash
+buf lint
+```
+
+### Breaking Change Detection
+
+To check for breaking changes against the `master` branch on the BSR:
+```bash
+buf breaking --against buf.build/tcn/exileapi:master
+```
+
+## GitHub Actions
+
+A GitHub Actions workflow (`.github/workflows/buf-push.yaml`) is configured to automatically:
+
+1.  **Lint & Check Breaking Changes:** On pushes to the `master` branch.
+2.  **Push to BSR:** On pushes to the `master` branch and when tags matching `v*` are created.
+
+This ensures that the definitions in the BSR are always up-to-date with the `master` branch and tagged releases.
+
+## Contributing
+
+[Add contribution guidelines here if applicable]