Automatically-update Docker Repo description

.github/workflows/docker.yml

@@ -26,6 +26,12 @@ jobs:
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Docker Hub Description
+        uses: peter-evans/dockerhub-description@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+          repository: libreddit/libreddit
       - name: Build and push
         uses: docker/build-push-action@v2
         with: