Breaking change due to mode rename

[blink1073]

The vue mode depends explicitly on jade.

https://github.com/codemirror/CodeMirror/blob/master/mode/vue/vue.js#L15

We found this when trying to WebPack all of the modes.

[jasongrout]

More context - 5.18.0 release today had the note "The mode formerly known as Jade was renamed to Pug."

[blink1073]

Code (using asynchronous-style WebPack import):

require([`codemirror/mode/${mode}/${mode}`], () => {

Error:

ModuleNotFoundError: Module not found: Error: Cannot resolve 'file' or 'directory' ../jade/jade in /Users/ssilvester/workspace/jupyter/lab/jupyterlab/node_modules/codemirror/mode/vue

[blink1073]

Confirmed that replacing all occurrences of jade with pug in vue.js fixes the issue.

[marijnh]

Thanks for noticing that. Attached patch should help.

[blink1073]

Thank you for the quick fix, and for CodeMirror in general!