I really like angular's documentation where you have the source and beside it the runtime result. for example https://angularjs.org/#wire-up-a-backend
I am looking for tools to help me get similar results. Write code once, in a maintainable manner (preferably separate files), and have them shown on the page in tabs with the runtime result next to it.
I good bet for this sort of thing is Jupyter notebooks - in it you can mix documentation, in markdown, formulae, in MathJax, code, in a number of languages, always including Python but a number of other languages are supported depending on which Kernel(s) that you have installed, with syntax highlighting and the results of executing that code including images, graphs, plots, etc.
The notebooks can be published, with the results, using NBViewer or as HTML or pdf format files.
Jupyter and the majority, if not all, of the Kernels are:
