Merge pull request jupyterlab#172 from jupyterlab/archive

Mention this project is archived.

.github/ISSUE_TEMPLATE/issue.md

@@ -0,0 +1,14 @@
+---
+name: Issue
+about:
+title: ""
+labels:
+assignees: ""
+---
+
+<!--
+Welcome!
+
+This project is archived as the toc extension is now part of JupyterLab. Please open any issue on that repository:
+https://github.com/jupyterlab/jupyterlab/issues/new/choose
+-->

README.md

@@ -1,5 +1,9 @@
 # jupyterlab-toc
 
+## Archived
+
+**This project is archived. Development is now happening in https://github.com/jupyterlab/jupyterlab.**
+
 This extension was added to the core JupyterLab extensions for JupyterLab 3.0. Anyone using JupyterLab < 3.0 should use this extension, but anyone using JupyterLab >= 3.0 will already have this extension installed with the core JupyterLab extensions. Any issues or pull requests should be added to the [JupyterLab repo](https://github.com/jupyterlab/jupyterlab). 
 
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