Use an Outliner app to build diagnostic aid for help desk operators
I remember many years back when I still did technical field support on desktop computers (before we regressed to Windows 95 and GUI interfaces) we used a DOS-based outliner called Symantec GrandView around the late 1980's to build up a knowledge base of symptoms where the outliner led a call operator through the questions to ask, and which then branched out to further related questions to arrive at possible solutions. As the technical people, we had to help populate and build this repository by expanding the questions and answers. It worked very well and also served as a learning aid for new technicians.
An outliner is basically a hierarchical tree of linked items. You can use them for even running simple projects, todo lists, lists of books, movies, website logins, personal contacts, or things to do.
There are a number of these apps around and a typical open source Windows/Linux app is TreeLine at http://treeline.bellz.org/feature.html which even can create mini-forms. For really cross-platform syncing you may want to look at Dynalist (although it grew from open source Treenote, Treenote is no longer in development) at https://dynalist.io which is free and unlimited use except for more advanced features which require a monthly payment.
Yes pro helpdesks will have expensive trouble ticket systems todo but if you're a small business taking on new staff or dealing with product support a simple outliner can go a long way at zero cost.