IBX-5857: Fix tall right ToC

[adriendupuis]

Question	Answer
JIRA Ticket	IBX-5857
Versions	N/A
Edition	N/A

Issue

When the right table of content is taller than the available height, the bottom was mostly hidden, the current item coud be outside the viewport, this ToC was coming into view only when scrolling down to reach the bottom of the page, event there, the footer came over to hide the last items.

Examples:

• Too tall: https://doc.ibexa.co/en/master/permissions/permission_use_cases/
• Fit in: https://doc.ibexa.co/en/master/permissions/policies/

Fix

• Add a scrollbar so the ToC can be used before stating to scroll the central content.
• Scroll the current item into view.

Example:

• Too tall: https://ez-systems-developer-documentation--2338.com.readthedocs.build/en/2338/permissions/permission_use_cases/
• Fit in: https://ez-systems-developer-documentation--2338.com.readthedocs.build/en/2338/permissions/policies/

Related

Documentations:

• Developer: IBX-5857: Fix tall right ToC #2338
• User: IBX-5857: Fix tall right ToC documentation-user#281
• Connect: ibexa/documentation-connect#34

Checklist

• Text renders correctly
• Text has been checked with vale
• Description metadata is up to date
• Redirects cover removed/moved pages
• Code samples are working
• PHP code samples have been fixed with PHP CS fixer
• Added link to this PR in relevant JIRA ticket or code PR

[mnocon]

Thanks!