Re: [PATCH v7 4/4] docs: make the purpose of using app password for Gmail more clear in send-email

> +Gmail does not allow using your regular password for `git send-email`.
>  If you have multi-factor authentication set up on your Gmail account, you can
>  generate an app-specific password for use with `git send-email`. Visit
>  https://security.google.com/settings/security/apppasswords to create it.
>  
> -You can also use OAuth2.0 authentication with Gmail. `OAUTHBEARER` and
> -`XOAUTH2` are common methods used for this type of authentication. Gmail
> -supports both of them. As an example, if you want to use `OAUTHBEARER`, edit
> -your `~/.gitconfig` file and add `smtpAuth = OAUTHBEARER` to your account
> -settings:
> +Alternatively, instead of using an app-specific password, you can use
> +OAuth2.0 authentication with Gmail. OAuth2.0 is more secure than
> +app-specific passwords, and works regardless of whether you have multi-factor
> +authentication set up.