Add a license (MIT/Apache). Consider the license of the data (could be problematic...)

So I thought I'd follow up on this. I don't know where the `pws.txt` is from but the `SecLists` link is `CC BY-SA 3.0` see [hear](https://www.owasp.org/index.php/Projects/OWASP_SecLists_Project) and [hear](https://github.com/danielmiessler/SecLists/issues/99). `ShareAlike` is compatible with changing the licence. On the other hand the passwords may be stolen goods, or non creative work so copyright may not apply.

Alternative, make the password file a compile time environment variable that the program processes all of. Do not provide the file but link to some suggested ones for people to use. It would make distributing compiled `js/wasem` files hard.

Start by tracing the provenance and licensing of pws.txt, including the linked SecLists references. Then inspect how the password data is included in the Rust build and how the js/wasem artifacts are distributed. Done means the project license and the data-distribution approach are decided and documented.

Written by the indexing model from the issue text.