DOC-2562: Add live-demo for document converters and full feature demo pages.

[kemister85]

Ticket: DOC-2562

Site: Full Feature Demo Site: ExportWord Site: ExportPDF Site: ImportWord

Changes:

• add new demos to plugin pages.

Pre-checks:

• [x] Branch prefixed with feature/<version>/, hotfix/<version>/, staging/<version>/, or release/<version>/.

Review:

• [x] Documentation Team Lead has reviewed

[FarzadHayat]

@kemister85

• [x] Now that the plugins are being added to the featured featured demo, we can remove them from the excluded plugins list here: https://github.com/tinymce/tinymce-docs/blob/1652b64b2a8292dc6703341befe814273b1320d9/modules/ROOT/pages/full-featured-premium-demo.adoc?plain=1#L26-L34