fix(main): Handle errors & logic when templating to directory

This does several changes to the new "template to directory" feature
introduced in the previous commit:

1. Errors are now "handled". In classic Go-style, it is of course all
   too easy to do absolutely nothing with errors, but we can't have
   that. I'm onto you, Renee French's husband!

2. Resource sets containing similarly named files are now templated
   correctly by prepending the resource set name to the filename.

3. In the same vein as the previous point, nested resource sets are
   now also output correctly by replacing slashes (`/`) with
   dashes (`-`) to guarantee that the output files are a flat list.

Some minor cosmetic fixes have also been applied.

0 files changed, 0 insertions, 0 deletions