check the badge

.github/workflows/badges.yml

@@ -0,0 +1,20 @@
+name: RTD Preview
+on:
+  pull_request_target:
+    types: [opened]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  binder:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v6
+        with:
+          github-token: ${{secrets.GITHUB_TOKEN}}
+          script: |
+            const issue_number = context.issue.number;
+            const {repo, owner} = context.repo;
+            const body = `[![lite-badge](https://jupyak.rtfd.io/en/latest/_static/badge.svg)](https://jupyak--${issue_number}.org.readthedocs.build/en/${issue_number}) :point_left: Try it on ReadTheDocs`;
+            github.rest.issues.createComment({issue_number, owner, repo, body});

docs/conf.py

@@ -1,5 +1,7 @@
 """documentation for ``jupyak``."""
 import datetime
+import json
+import os
 import re
 from pathlib import Path
 
@@ -24,6 +26,7 @@
     for ext in ["toml", "yaml", "yml", "json"]
     if (ROOT / f"jupyak_config.{ext}").exists()
 ]
+ALLOW_NO_CONFIG = json.loads(os.environ.get("JUPYAK_ALLOW_NO_CONFIG", "0").lower())
 
 # metadata
 author = PROJ_DATA["project"]["authors"][0]["name"]
@@ -101,7 +104,7 @@
 if REPO_INFO is not None:
     html_context = {**REPO_INFO.groupdict(), "doc_path": "docs"}
 
-if JUPYAK_CONF_CANDIDATES:
+if ALLOW_NO_CONFIG or JUPYAK_CONF_CANDIDATES:
     html_sidebars["*"] = [
         "demo",
         *html_sidebars["*"],