Strikethrough plugin

[jni759]

Nice work!
Trying to add a 'strikethrough' button to Toolbar meny. I'm guessing the plugin (strikethrough) is not in the build.
How does one add that plugin manually?
I'm trying to stay away from javaScript but here I am.. :)

[qmmughal]

Good catch — and sorry for the delay.

Why it fails: the bundled ClassicEditor build (wwwroot/js/ckeditor.js) does not include the Strikethrough plugin (confirmed: no Strikethrough in that build). The toolbar in CKEditorInterop.js also has no 'strikethrough' item (it does include 'underline').

How to add it:

1. Rebuild CKEditor 5 with the Strikethrough plugin (CKEditor online builder or your own webpack/vite build)
2. Replace wwwroot/js/ckeditor.js
3. Add 'strikethrough' to toolbar.items in CKEditorInterop.js

Documented under README Known gaps. Leaving open as a docs/enhancement tracker; happy to review a PR that swaps in a build with strikethrough enabled.