Hi there!
I started using Codemirror 6 and it looks very promising. Congratulations for the work! The HTML autocompletion/suggestion works quite well with opening tags. However, it looks like the UX could be improved. I mean by inserting at least closing tags associated with the opening tags.
For instance, when you write <sty, style is suggested. Upon selection, you get <style. What I suggest is to have a mean to get <style></style> and the cursor moves between the opening and closing tags.
More generally, a behavior similar to IntelliJ Idea autocompletion would be fantastic but I have no idea about the work it requires. Taking their IDE as an example, they can auto-close tags, move the cursor to appropriate attributes and body in sequence and this with any language. For instance, autocompleting func in JS produces a full function definition function f() { }, automatically selects f for changing the name and upon name validation moves the cursor between ( and ) to edit parameters.
Since codemirror 6 is still in its early days and it seems that some design decisions are in progress, I was wondering if there is any plan to support such feature(s) in the core library?