Add email to arg types

modules/ROOT/pages/args.adoc

@@ -36,6 +36,7 @@ A full list of argument types are below;
 | ascii                       | <<arg-textbox,Textbox>>           | a-z (case insensitive), 0-9, but no spaces or punctuation
 | ascii_identifier            | <<arg-textbox,Textbox>>           | Like a DNS name, a-Z (case insensitive), 0-9, `-`, `.`, and `_`. 
 | ascii_sentence              | <<arg-textbox,Textbox>>           | a-z (case insensitive), 0-9, with spaces, `.` and `,`. 
+| email                       | <<arg-textbox,Textbox>>           | An email address.
 | very_dangerous_raw_string   | <<arg-textbox,Textbox>>           | Anything. This is **incredibly dangerous**, as effectively people can type anything they like, including executing additional commands beyond what you specify. Absolutely should not be used unless your OliveTin instance can only be used by people you trust entirely.
 | regex:...                   | <<arg-textbox,Textbox>>           | Version 2024.03.081 and above support custom regex patterns. See <<args-custom-regex,Custom regex arguments>>. 
 | int                         | <<arg-textbox,Textbox>>           | Any number, made up of the characters 0 to 9. Negative numbers are not supported.