Is your feature request related to a problem? Please describe.
According to the official docs, the default path for the Userpass auth method is userpass:

This documentation assumes the Username & Password method is mounted at the default /auth/userpass path in Vault. Since it is possible to enable auth methods at any location, please update your CLI calls accordingly with the -path flag.

However, the path property of the UserPass auth method in the External Secrets configuration defaults to user. See the VaultUserPass struct.

Also, the documentation states the user path only as an example, not as the default value:

Path where the UserPassword authentication backend is mounted in Vault, e.g: “user”

This leads to errors and time-consuming troubleshooting if the configured Vault uses the default path and users omit the path property because they assume that the default value of External Secrets is the same.

Describe the solution you'd like
The long-term solution would be to adjust the default value.

Describe alternatives you've considered
Since adjusting the default value is a breaking change, explicitly mentioning user as the default value in the docs would already help to avoid initial configuration errors.

Additional context
-