docs: update default auth-type to "web" in npm adduser documentation

Author: jpg619

content/cli/v8/commands/npm-adduser.mdx

@@ -81,8 +81,7 @@ npm init --scope=@foo --yes
 
 #### `auth-type`
 
-- Default: "legacy"
-- Type: "legacy", "web", "sso", "saml", "oauth", or "webauthn"
+- Default: "web"
 
 NOTE: auth-type values "sso", "saml", "oauth", and "webauthn" will be removed in a future version.