Help: Fix typo and improve docs for --debug-find-pkg|var options

Amends d7b18895bc (cmake: Add filtered debug-find options, 2021-12-07)

Help/manual/cmake.1.rst

@@ -250,16 +250,17 @@ Options
  See also the :variable:`CMAKE_FIND_DEBUG_MODE` variable for debugging
  a more local part of the project.
 
-``--debug-find=<pkg>[,...]``
+``--debug-find-pkg=<pkg>[,...]``
  Put cmake find commands in a debug mode when running under calls
- to ``find_package(<pkg>)``, where ``<pkg>`` is an entry in the given
- comma-separated list of case-sensitive package names.
+ to :command:`find_package(\<pkg\>) <find_package>`, where ``<pkg>``
+ is an entry in the given comma-separated list of case-sensitive package
+ names.
 
  Like ``--debug-find``, but limiting scope to the specified packages.
 
 ``--debug-find-var=<var>[,...]``
  Put cmake find commands in a debug mode when called with ``<var>``
- as the return variable, where ``<var>`` is an entry in the given
+ as the result variable, where ``<var>`` is an entry in the given
  comma-separated list.
 
  Like ``--debug-find``, but limiting scope to the specified variable names.