bench: TemplateNotFound "default"

I discovered the issue for the `TemplateNotFound` in use `bench 'ls /usr/bin | wc -l' --output a.html` command.
That don't generate the `a.html` file for above command.

My system is the wsl2 for the ubuntu, and install the tool use the `brew install bench`.

Follow is the picture for the detailed of the error, I don't find about the information in the `help` option and the `man bench`.


Start by reproducing `bench 'ls /usr/bin | wc -l' --output a.html` in the reported WSL2 Ubuntu setup and inspect the `TemplateNotFound` error. The issue names no source file or test; done would require determining why `a.html` is not generated and making the command work or clearly documenting the required template or limitation.

Written by the indexing model from the issue text.