Fix documentation for apply fixed
Fix documentation for apply fixed

The old "fixed" and "endfixed" are no longer used (and afaict don't
work).  You have to use "apply fixed" and "end apply" instead.

Fixes issue #789

Signed-off-by: Martin Michlmayr <204da078bb794ca7b065b3ff55e0f162ee76e3a2@cyrius.com>

ledger/ledger,afh/ledger,afh/ledger,afh/ledger,ledger/ledger,ledger/ledger,afh/ledger,ledger/ledger,ledger/ledger,afh/ledger