Document `editor-analyze` inputs/outputs.

Short description Document the editor-analyze API's better, to answer the following questions:

How is the input represented (terms of AnalysisAction sort).
How is the output represented (terms of the AnalysisResult sort, including Full and Update).

Problem description. The input and output of the solver wrapper strategies is not documented very well.

Describe the solution you'd like A good overview on https://www.spoofax.dev/references/statix/stratego-api/.

metaborg / nabl