so, this is interesting.
the homepage (square.github.io) is very much the same as the github organization page (github.com/square). the project pages (square.github.io/dagger) similar to the github repositories (github.com/square/dagger).
I think it's worth the effort to build both of them. it allows us to customize content and style, add and remove some stuff.
for the project page that means, corporate identity, a nice overview of projects (instead of the project lists ordered by last update), and links to social media.
for the project pages this means, more prominent placement of the readme (instead of the source code view), a navigation bar for the readme's sections and prominent placement of links to apidocs, social media, and download links to the most recent version.