Add example for --rich-data option.
Add example for --rich-data option.

And add explanation for associated tags.

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Conflicts:
	doc/ledger3.texi

afh/ledger,jwakely/ledger,ledger/ledger,jwakely/ledger,duncanmortimer/ledger,duncanmortimer/ledger,afh/ledger,duncanmortimer/ledger,jwakely/ledger,paulbdavis/ledger,ledger/ledger,afh/ledger,ledger/ledger,paulbdavis/ledger,duncanmortimer/ledger,ledger/ledger,duncanmortimer/ledger,afh/ledger,afh/ledger,paulbdavis/ledger,jwakely/ledger,duncanmortimer/ledger,paulbdavis/ledger,ledger/ledger,paulbdavis/ledger,paulbdavis/ledger,paulbdavis/ledger,jwakely/ledger,jwakely/ledger,duncanmortimer/ledger,jwakely/ledger