Update regex.rst

source/additional_information/regex.rst

@@ -4,7 +4,7 @@ Regular Expressions
 
 * ^ Start of the string
 * $ End of the string
-* ? optional
+* ? optional example 1? makes the 1 optional
 * \\d{10}  10 digits
 * ( and ) gets matching digits inside brackets sets a $1 and second set of brackets creates $2
 * ^\\+?1?(\\d{10})$   10 to 11 digits and e164 format sets $1 to 10 digits