chore: add documentation for docker image

Dockerfile

@@ -18,4 +18,5 @@ COPY --from=build-env /src/main /usr/bin/local-da
 
 EXPOSE 7980
 
-CMD ["local-da", "-listen-all"]
+ENTRYPOINT ["local-da"]
+CMD ["-listen-all"]

Makefile

@@ -14,6 +14,12 @@ build:
 	@go build -o build/ ${LDFLAGS} ./...
 .PHONY: build
 
+## docker-build: Build local-da docker image.
+docker-build:
+	@echo "--> Building local-da docker image"
+	@docker build -t local-da .
+.PHONY: docker-build
+
 ## help: Show this help message
 help: Makefile
 	@echo " Choose a command run in "$(PROJECTNAME)":"

README.md

@@ -6,6 +6,10 @@ It is intended to be used for testing DA layers without having to set up the act
 
 ## Usage
 
+### local-da binary
+
+To build and run the local-da binary:
+
 ```sh
 make build
 ./build/local-da
@@ -26,6 +30,15 @@ $ ./build/local-da -listen-all
 2024/04/11 12:23:34 Listening on: 0.0.0.0:7980
 ```
 
+### Docker
+
+You can also run the local-da service using docker:
+
+```sh
+make docker-build
+docker run --rm -p 7980:7980 local-da
+```
+
 ### MaxBlobSize
 
 ```sh