Clean up website TOC + "previous"/"next" buttons

[dominiquesydow]

Description

Clean up website TOC tree and "previous"/"next" buttons.

Todos

• Swap order of talktorial list and collection in TOC to avoid mixed-up "previous"/"next" buttons, see discussion in Website: Some "previous" and "next" buttons are mixed up #143
• Sections under "External Resources" were not part of the "previous"/"next" buttons; split resources by 1. dependencies ("Packages and webservers used in TeachOpenCADD") and 2. tutorials/collections for further reading ("External tutorials and collections") - these terms are now part of the TOC and "previous"/"next" buttons
• Remove automatic TOC generation for the API modules/functions (too verbose for our current purposes)
• Remove "WIP" flag from website - I think we are ready for this :)
• Check website rendering offline

Questions

None.

Status

• Ready to go