Add documentation for SymbolConfigurator.

From SymbolConfigurator removed getFirstSymbolKey() method.
In this case I understand mistake in implementation of getFisrtKey().
So I change it to return first key according min length of key.
Remove default type for Character of KeyConfigurator.
Add documentation for SymbolRun.
Add documentation for SymbolValidator.
Merge branch 'add-missed-documentation' into development