Fix frontend hijacking /docs in development

{{cookiecutter.project_slug}}/frontend/Dockerfile

@@ -25,3 +25,4 @@ FROM nginx:1.15
 COPY --from=build-stage /app/dist/ /usr/share/nginx/html
 
 COPY --from=build-stage /nginx.conf /etc/nginx/conf.d/default.conf
+COPY ./nginx-backend-not-found.conf /etc/nginx/extra-conf.d/backend-not-found.conf

{{cookiecutter.project_slug}}/frontend/nginx-backend-not-found.conf

@@ -0,0 +1,9 @@
+location /api {
+    return 404;
+}
+location /docs {
+    return 404;
+}
+location /redoc {
+    return 404;
+}