Override default viewer on Binder to open MySTs as JupyText Notebooks

binder/labconfig/default_setting_overrides.json

@@ -0,0 +1,8 @@
+{
+    "@jupyterlab/docmanager-extension:plugin": {
+        "defaultViewers": {
+            "markdown": "Jupytext Notebook",
+            "myst": "Jupytext Notebook"
+        }
+    }
+}

postBuild → binder/postBuild

@@ -2,6 +2,10 @@
 set -e  # don't allow errors to fail silently
 echo `which pip`  # in case the wrong `pip` is used, this will let us debug
 
+# See https://github.com/mwouts/jupytext/issues/803#issuecomment-982170660
+mkdir -p ${HOME}/.jupyter/labconfig
+cp binder/labconfig/* ${HOME}/.jupyter/labconfig
+
 # Install and enable extensions...
 pip install "jupytext[myst]>=1.13.3"
 jupyter nbextension install --py jupytext --user