Correction procédure de démarrage et mise à jour du README

Makefile

@@ -13,13 +13,13 @@ build-server:
 
 deps:
 	cd client && npm install
-	env GO111MODULE=off go get github.com/cortesi/modd/cmd/modd
+	go get ./...
 
 up: build-docker
 	docker-compose up
 
 watch:
-	$(GOPATH)/bin/modd
+	go run github.com/cortesi/modd/cmd/modd
 
 down:
 	docker-compose down -v --remove-orphans
@@ -43,4 +43,9 @@ test:
 	go test -v ./...
 
 hydra-shell:
-	docker-compose exec hydra /bin/sh
+	docker-compose exec hydra /bin/sh
+
+clean: down
+	rm -rf client/node_modules bin data .env internal/graph/generated internal/graph/server.go
+	rm -rf vendor
+	go clean -modcache