add glob support for nomad jobs defaulting to **/*.nomad

[prabirshrestha]

This adds support for glob pattern for nomad jobs which is breaking if you set it in the past. I had README.md file and it was trying to submit a job. This would also allow us to organize inside a folder.

This would also lay as a foundation for adding support for nomad variables.

jobs/traefik/README.md
jobs/traefik/traefik.nomad
jobs/traefik/traefik.nomad.vars.hcl

Currently not a fan of the name --path after this change. I'm thinking --nomad-jobs jobs/**/*.nomad.hcl --nomad-vars jobs/**/*.nomad.vars.hcl. I explicitly prefixed with nomad since in future it might make sense to add waypoint to support this use case. Thoughts on this change or can do later when I send variables PR later.

I have set the default path to be **/*.nomad. And also updated the README.md examples so it works for those who copy paste to try it out.