Document interactiuon of Maven and Ant settings

[elharo]

Affected version

HEAD

Bug description

We need to be deliberate about this. It's not clear the existing behavior is intentional.

src/site/markdown/index.md:44: The default user settings path is incomplete. The implementation (AetherUtils.findUserSettings()) checks ${user.home}/.ant/settings.xml first, then falls back to
${user.home}/.m2/settings.xml. This precedence should probably be documented.