mention custom email usage

README.md

@@ -7,7 +7,7 @@
 and receive emails to the temporary email address. It uses 1secmail's [API](https://www.1secmail.com/api/)
 to receive emails.
 
-By default, emails will be generated by random unless the `--generate` argument is followed by the desired username.
+By default, emails will be generated by random unless the `--generate` argument is followed by the desired email address.
 
 By default `w3m` is used to render the HTML emails on the terminal.
 But if you prefer another text based web browser or would rather view the email in a GUI web browser such as Firefox, simply
@@ -49,7 +49,7 @@ usage: tmpmail [-h] [--generate] [--text] [--browser BROWSER] [--recent] ID
 optional arguments:
 -h, --help           Show this help message
     --version        Print version
--g, --generate       Generate a new email address. You may aslo pass a custom username along with this flag
+-g, --generate       Generate a new email address. You may aslo pass a custom email address along with this flag
 -r, --recent         View the most recent email
 -t, --text           View the email as raw text, where all the HTML tags are removed
 -b, --browser        Change the browser that is used to render the HTML of the email (default: w3m)
@@ -64,7 +64,7 @@ xoithrjagpx@1secmail.net
 
 Create custom email
 ```console
-$ tmpmail --generate mycustomemail
+$ tmpmail --generate mycustomemail@1secmail.com
 mycustomemail@1secmail.com
 ```