oh well it isn't supported

.devcontainer/devcontainer.json

@@ -1,17 +0,0 @@
-{
-    "name": "Writer app",
-    "dockerFile": "Dockerfile",
-    // Use 'appPort' to create a container with published ports. If the port isn't working, be sure
-    // your server accepts connections from all interfaces (0.0.0.0 or '*'), not just localhost.
-    "appPort": [
-        1234,
-        3000
-    ],
-    // Use 'settings' to set *default* container specific settings.json values on container create. 
-    // You can edit these settings after create using File > Preferences > Settings > Remote.
-    "settings": {
-        "terminal.integrated.shell.linux": "/bin/zsh"
-    },
-    // Specifies a command that should be run after the container has been created.
-    //"postCreateCommand": "npm i && cd frontend && npm i",
-}