add hackmd to packages

packages/app/docker/Dockerfile

@@ -110,6 +110,7 @@ COPY packages/plugin-lsx packages/plugin-lsx
 COPY packages/slack packages/slack
 COPY packages/ui packages/ui
 COPY packages/remark-growi-plugin packages/remark-growi-plugin
+COPY packages/hackmd packages/hackmd
 
 # build
 RUN yarn lerna run build