Feature request: download specific file(script) from Git, not just release

[needleshaped]

Use case:

There are number of scripts for a small tasks, that one would usually download with wget/curl.
As BIN tries to cover the niche of Git(Hub)-sourced standalone programs, I feel it would be natural for it to support simple scripts

For example:

• https://github.com/drwetter/testssl.sh - very famous, error=Could not find any compatible files
• https://github.com/Matty9191/ssl-cert-check/, error=repository Matty9191/ssl-cert-check does not have releases

Alternatives:

• self-managed script with wget/curl
• git clone (too much)

[needleshaped]

Similar issues: #214, #179