Merge pull request #6647 from jtpio/theme-cookiecutter

Add theme cookiecutter to the docs and release check-list

RELEASE.md

@@ -97,6 +97,7 @@ JupyterLab itself, run `jlpm run bumpversion major`.
   - [ ] https://github.com/jupyterlab/extension-cookiecutter-ts
   - [ ] https://github.com/jupyterlab/mimerender-cookiecutter
   - [ ] https://github.com/jupyterlab/mimerender-cookiecutter-ts
+  - [ ] https://github.com/jupyterlab/theme-cookiecutter
   - [ ] https://github.com/jupyterlab/jupyter-renderers
   - [ ] https://github.com/jupyterhub/jupyterlab-hub
 - [ ] Add a tag to [ts cookiecutter](https://github.com/jupyterlab/extension-cookiecutter-ts) with the new JupyterLab version

docs/source/developer/extension_dev.rst

@@ -43,7 +43,7 @@ A plugin adds a core functionality to the application:
    interface, by exporting a plugin object or array of plugin objects as
    the default export.
 
-   We provide two cookie cutters to create JuptyerLab plugin extensions in
+   We provide two cookie cutters to create JupyterLab plugin extensions in
    `CommonJS <https://github.com/jupyterlab/extension-cookiecutter-js>`__ and
    `TypeScript <https://github.com/jupyterlab/extension-cookiecutter-ts>`__.
 
@@ -303,6 +303,9 @@ location of your choice, and start making desired changes.
 The theme extension is installed in the same way as a regular extension (see
 `extension authoring <#extension-authoring>`__).
 
+It is also possible to create a new theme using the
+`TypeScript theme cookiecutter <https://github.com/jupyterlab/theme-cookiecutter>`__.
+
 Standard (General-Purpose) Extensions
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~