Non-categorized pages end up on on the site without styling
A user may go to a stellar-core page with the url https://www.stellar.org/developers/stellar-core/learn/admin.html. Out of curiosity, the user deletes the learn/admin.html and gets to https://www.stellar.org/developers/stellar-core/. However, that root stellar-core page looks like this:

Why?
This happens because all pages on the developer site is supposed to be under one of the four categories: Learn, Reference, Tools, and Beyond Code. It was decided a while back that some files did not need to be put on the developers site and thus were not categorized (not in a folder with the above name).
There are two solutions
Option 1: Exclude non-categorized files in build process
In the gulp process, instead of symlinking to the project docs page, we can symlink to these specific four folders.
Option 2: Include these files by categorizing them
This would involve moving the files from the docs folder root to their specific folders.
I think option 2 is the better way to go. I speculate some people would believe the developers site to be the source of all truth and not look at other docs in repos (sometimes I fall into this thinking too).
It is counterproductive to have our docs split up.
Another example of split up docs is the js-stellar-sdk project-root readme. This readme contains useful instructions but is nowhere to be found on the developers website.
Agree that option two would be preferable. Either way though, we do need to fix this, since a developer did find this page and wrote in about it.