t/26 - add Production Pack demo + CKE5/CKBox version bump

[usqr]

Closes: #26

[mlewand]

Quite a big PR, it would make sense for you to pass more context what the change is all about.

Since the changes were significant let's also ask our great @ckeditor/qa-team team to test the demos before going with next review round. @usqr can you ask them and handle the communication (including information what was changed and what was the reason for it)?

[usqr]

@mlewand So some background - There are lots of changes going on in nova on demos (bug fixes, feature updates, new demos). With that amount of work and a small team we don't have time to keep public repo up to date at all times so when we have some more time in a sprint we try to bundle those changes.

• As the public repo should be "near mirror image" of the private one there will be some css/html/7/or content changes changes as we update/optimize/fix demos in the private one - the css/content are copied directly so any changes have to be reflected in the public one
• there are usual version bumps here
• new PP demo (kinda self explanatory)
• new features added (the demos on nova are evolving fast and it is hard to keep up to date with all the changes - especially that this repo is of least importance [tbh for ours and your teams :shrug: ])

I will squash all the bugs and pass it on to the QA team. :+1:

[usqr]

Resolutins are not necessary any more.

Resolutions removed

• It's a big PR so lest ask QA Team to test the demos,

QA task: cksource/qa-internal#239

• One thing i've noticed - in Full featured demo there isn't Show blocks feature enabled. (on ckeditor.com also),

This Repo just reflects CKEditor.com demos - most of the changes are requested/approved by marketing... :man_shrugging:

• new Productivity Pack demo - for me it looks a bit odd without any information why it does not work out of the box (i would add some info text in index.html),
• similar situation in user-interface-document demo, but there is also o visibility issue, when column on the left is empty (it's reserved place for document outline),
• in Full featured demo in content we mention about CKBox, but (same as above) to make it work we need to look in the code and read about missing license keys - info in index.html would be best from my point of view - but of course - discussion needed 🙂

This an issue of the fact that we are using premium features in those demos we can't provide licence keys/token/other access data in public facing demo yet we want to have feature parity with the demos on cke.com.
it's the same situation with source code for the demos in the docs: https://ckeditor.com/docs/ckeditor5/latest/examples/builds-custom/collaborative-document-editor.html#editor-example-configuration
But I agree that adding some sort of info in the index files would be good. WDYT @Witoso :thinking:

[charlttsie]

@usqr Slash command plugin is not added to the user-interface-button-grouping demo code (it's present on ckeditor.com).