Evaluate the navigation before October 1st

[ericearl]

Navigation should be inspected per top tab for completeness, cohesion, and ease of use without using the search functionality. Reviews can either be conducted in a post to this issue, or as a PR for further review. @iamdamion Should receive and respond to the (at least 2) mentor reviews.

[bendhouseart]

• About -> left navigation pane is empty
• Datasets -> The left navigation pane is a bit empty, but it's fully functional
• Impact -> left navigation pane is empty, but again that isn't a navigation issue just a note.
• Merch -> is great no notes

Okay all the navigation took me to where I expected it. I think uniformity is overrated with respect to how each page appears.

[christinerogers]

Remi and Anthony's evaluation : this is resolved nicely.
Followups are already documented with issues elsewhere or will be opened / cross-linked by @Remi-Gau

[Remi-Gau]

potential follow up or more precise issues to help improve navigation:

• rework BIDS app FAQ  #525
• create a separate "entry" to list places where to find datasets #356
• Add a section "for editors" on website #359
• Split the "impact" section in several pages #452
• Create a how-to section #471
• how to section for BIDS apps #511
• Reorganize the standard section of the website #518