With file:// one can supply a file name which contains a URL per line.
--single-threaded disables parallelizm.

Most of all, abstract HTTP Client.
Test reporters.
Test using mock http client.
Test recursive and non-recursive.
Test Axios client separately.

Add timeout, accepted-code, ignore-prefixes and skip.
Include processing of these options.
Track request time (poorly).

Split files.
Add reporters (Console for now).
Add colors.

Parse HTML and extract a few types of links.
Has tests, coverage and debugging scripts.