There are a couple of folders in different locations on my hard drive that contain resources I use a lot while coding (documentation, links, ...) but aren't really related to any specific one of my projects.
How can I have the Eclipse Package Explorer show such a folder that is not inside one of my existing projects?
One potential use: Quick way to transfer "External Tool Configurations" from one Eclipse install to another? (see comments to accepted answer...)
Since everything that the Package Explorer shows has to be in a project (as pointed out by @greg-449), one needs to create a dummy-project in the required location:
Minor cosmetic issue: Eclipse will save a .project file in that folder...
Aside:
To make this folder appear at the top of the list, one can give it a name like _Documentation_ as Eclipse sorts the underscore before any letters.