This commit adds a new UML class diagram that illustrates the parallel processing components
and their relationships within the system architecture. The diagram provides visual representation
of how different modules interact in a parallel computing environment.
Move UML PDF to doc/ and update .gitignore. Normalize includes,
whitespace and function signatures across headers/sources and add
concise class/function documentation. Fix RandomBot so the mine
limit is computed once and simplify DigDeepBot/SortBot mining logic.
Tidy World/Game initialization, error handling, and minor const/var
clarifications for readability and correctness
fegger