feat: support c++ targets

Author: v0y4g3r

Makefile

@@ -2,7 +2,7 @@
 
 BUILDER_CONTAINER=namely/protoc-all:1.51_1
 
-all: rust go java
+all: rust go java cpp
 
 rust:
 	cargo build
@@ -19,3 +19,8 @@ java:
 	docker run -t -w /greptime-proto \
 		--entrypoint ./scripts/generate-java.sh \
 		-v ${PWD}:/greptime-proto ${BUILDER_CONTAINER}
+
+cpp:
+	docker run -t -w /greptime-proto \
+		--entrypoint ./scripts/generate-cpp.sh \
+		-v ${PWD}:/greptime-proto ${BUILDER_CONTAINER}