doc:power: add Zsh completion location and update Bash install location

This puts both scripts in the right spot on Gentoo, and shows the
suggested installed filename (not just the suggested directory).

diff --git a/doc/power.txt b/doc/power.txt
index b0e93eaa6805be6c00ac756332273532b699bcfa..ea8fc082c6d2d58062311759d1043eba6d674362 100644 (file)
--- a/doc/power.txt
+++ b/doc/power.txt
@@ -15,7 +15,9 @@ one!).  Basic instructions for installing the completion file for a
 given shell should be given in the completion script comments.
 
 Packagers should install these completion scripts in their system's
-usual spot (on Gentoo it's :file:`/etc/bash_completion.d/`).
+usual spot (on Gentoo, the Bash completion script should be installed
+as :file:`/usr/share/bash_completion/be` and Z shell completion script
+should be installed as :file:`/usr/share/zsh/site-functions/_be`).
 
 XML-handling utilities
 ======================