Anchor link in the UG are not working

Under the Table of Content, only the bulleted points under "Features" are clickable and leads to the right portion, while the other headers are not linked to the section. Given that the headers appear to be all formatted in the same way, it gave the impression that all headers under the Table of Contents would be clickable.

_{[original: nus-cs2113-AY2223S2/pe-interim#44] [original labels: severity.VeryLow type.DocumentationBug]}