[PLUGINS] Standardize plugin ID naming conventions across hyphenated and underscored directories

[utksh1]

Summary

The repo currently mixes hyphenated and underscored plugin IDs (domain-finder, api_scanner, website-recon-2, etc.), which makes tooling and contributor expectations harder to normalize.

Scope

• Choose an explicit naming convention.
• Decide which existing IDs must remain for compatibility and which can be migrated or aliased.
• Document the rule for future plugin additions.

Acceptance criteria

• There is a documented plugin ID naming convention.
• Any compatibility-sensitive exceptions are explicit.
• New plugin guidance uses the chosen convention.

[anshul23102]

Interested in contributing under NSoC'26. This is a valuable issue. Happy to work on it.

/assign

[Rakshak05]

Hii @utksh1, I would like to work on this. Can you please assign it to me under GSSoC'26 contributor!?