fastexcel - update documentation to new version of fastexcel-reader

[andres-moreno]

The documentation lists [org.dhatim/fastexcel-reader "0.12.8" :exclusions [org.apache.poi/poi-ooxml]] as a required dependency.

Using this dependency results in a reflection warning. The documentation should be updated to require

org.dhatim/fastexcel-reader {:mvn/version "0.16.4"
                               :exclusions [org.apache.poi/poi-ooxml]}