Install multi-gitter

Dockerfile

@@ -1,3 +1,12 @@
+FROM ubuntu:22.04 as multi-gitter-image
+
+WORKDIR /multi-gitter
+
+RUN apt update && apt install curl --yes \
+    && touch ./multi-gitter && chmod +w ./multi-gitter \
+    && curl -s https://raw.githubusercontent.com/lindell/multi-gitter/master/install.sh -O \
+    && chmod +x install.sh && sh install.sh -b .
+
 FROM public.ecr.aws/lambda/nodejs:20 as build-image
 
 WORKDIR /usr/app
@@ -12,6 +21,7 @@ FROM public.ecr.aws/lambda/nodejs:20
 
 WORKDIR ${LAMBDA_TASK_ROOT}
 
+COPY --from=multi-gitter-image /multi-gitter/multi-gitter /usr/local/bin/multi-gitter
 COPY --from=build-image /usr/app/package.json /usr/app/package-lock.json /usr/app/dist ./
 
 RUN npm clean-install --omit dev