DOC-3243: Add table_default_header_rows and table_default_header_cols options to release notes and table options

[kemister85]

Ticket: TINY-13391 (release notes for DOC-3243)

Site: Staging

Changes:

• Added release note entry for new table_default_header_rows and table_default_header_cols options in 8.4.0-release-notes.adoc (Additions section), with xref links to the new config option docs
• Created table_default_header_rows.adoc config option partial
• Created table_default_header_cols.adoc config option partial
• Included both partials in table-options.adoc under "Controlling how tables are inserted"

---

Pre-checks:

• Branch is correctly prefixed: feature/8.4.0/DOC-3243_TINY-13391
• Build passes

[soritaheng]

Suggested change

In {productname} {release-version}, integrators previously had no way to set default header rows and columns when creating tables through the editor UI. This affected the accessibility of tables and required manual intervention for integrators aiming to meet accessibility standards. The new xref:table-options.adoc#table_default_header_rows[`+table_default_header_rows+`] and xref:table-options.adoc#table_default_header_cols[`+table_default_header_cols+`] options enable integrators to set the number of default header rows and columns for new tables created through the editor's UI, providing a supported way to meet accessibility requirements.

Previously, integrators had no way to set default header rows and columns when creating tables through the editor UI. This affected the accessibility of tables and required manual intervention for integrators aiming to meet accessibility standards. The new xref:table-options.adoc#table_default_header_rows[`+table_default_header_rows+`] and xref:table-options.adoc#table_default_header_cols[`+table_default_header_cols+`] options enable integrators to set the number of default header rows and columns for new tables created through the editor's UI, providing a supported way to meet accessibility requirements.