Improve article about ReportBook Parameters

[todorarabadzhiev]

Based on user feedback about https://docs.telerik.com/reporting/designing-reports/report-book/report-book-parameters

Give clear examples. NOTHING is clear, What is MyReportBook? why on earth do we need to assign its type name to a TypeReportSource? I thought we were delcaring a reportbook, but that's only done in the final example with a special warning NOT to do it that way, kind of? All this stuff could be shown in code much more easily than making a whole bunch of complex and simultaneously vague statements that all seem to contradict each other, with critical elements left out.