Remaining Developer Section Design Nits

[fabioberger]

Description

This PR:

• fixes many small design nits on the developer section pages.
• converts the remaining react-scroll links to use the component
• Makes "External exports" menu item clickable
• Breaks the docs log apart and makes the two sections link to the website home and the developers section home.

Testing instructions

Types of changes

Checklist:

• Prefix PR title with [WIP] if necessary.
• Prefix PR title with bracketed package name(s) corresponding to the changed package(s). For example: [sol-cov] Fixed bug.
• Add tests to cover changes as needed.
• Update documentation as needed.
• Add new entries to the relevant CHANGELOG.jsons.