fix: use ENTRYPOINT and CMD for proper argument handling (#454)

* fix: use ENTRYPOINT and CMD for proper argument handling

- Change from CMD to ENTRYPOINT + CMD pattern for better Docker practices
- ENTRYPOINT sets the executable that always runs
- CMD provides default arguments that can be overridden
- This allows container runtimes to properly append additional arguments
- Fixes issues with argument passing in container orchestration tools

Before: CMD ["./github-mcp-server", "stdio"]
After: ENTRYPOINT ["./github-mcp-server"] + CMD ["stdio"]

* address review feedback: use absolute path and improve comments

Author: JAORMX

Dockerfile

@@ -22,5 +22,7 @@ FROM gcr.io/distroless/base-debian12
 WORKDIR /server
 # Copy the binary from the build stage
 COPY --from=build /bin/github-mcp-server .
-# Command to run the server
-CMD ["./github-mcp-server", "stdio"]
+# Set the entrypoint to the server binary
+ENTRYPOINT ["/server/github-mcp-server"]
+# Default arguments for ENTRYPOINT
+CMD ["stdio"]