Squashed 'static-content/dotnet/' changes from cf1e20a..92d2a32

92d2a32 improve images with spec examples
c7bec57 polishing of new concept description
5811c54 add specification by documentation
e46cf7d use spec of assertequals in tutorial
afa4b1d idea how to describe process for "Documentation as Specification"
66bee03 documentation as specification

git-subtree-dir: static-content/dotnet
git-subtree-split: 92d2a325670909fbdeb2634cd1f2f9195f994326
specification by documentation