podchecker(1) complained about these, eg.

  *** WARNING: Verbatim paragraph in NAME section at line 3 in
               file tools/virt-host-validate.pod

Instead of embedding the pod information inside the respective
source files, store them in separate files.

This allows us to reduce the number of custom build rules as
most of the information can be inferred for the file name;
moreover, text editors are more likely to use proper syntax
highlighting for standalone pod files.