Most of the changes here remove trailing whitespace, but I also add
code to select "AUTHOR" or "AUTHORS" as appropriate instead of the
previous "AUTHOR(S)". The template for listing with an entry per line
is:
{{range $index, $entry := pipeline}}{{if $index}}
{{end}}{{$entry}}{{end}}
That range syntax is discussed in [1].
Also add a unit test, which tests both these whitespace changes and
also the earlier App.Description addition.
[1]: https://golang.org/pkg/text/template/#hdr-Variables