doc/tutorials/basic: update regexp.md

Fix repetitive typo

Closes #74
cuelang/cue#74

GitOrigin-RevId: 4b3470739a88f95d0e1b8e861ab9be3b13fde5d9
Change-Id: Ia50f7ad918be8dca826412b3b98dcce8183f3bba
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2868
Reviewed-by: Marcel van Lohuizen <[email protected]>

Author: noelmcloughlin

doc/tutorial/basics/regexp.md

@@ -9,7 +9,7 @@ The `=~` and `!~` operators can be used to check against regular expressions.
 The expression `a =~ b` is true if `a` matches `b`, while
 `a !~ b` is true if `a` does _not_ match `b`.
 
-Just as with comparison operators, these operators maybe be used
+Just as with comparison operators, these operators may be used
 as unary versions to define a set of strings.
 
 
@@ -36,4 +36,4 @@ b: true
 c: =~"^[a-z]{3}$"
 d: "foo"
 e: _|_ /* invalid value "foo bar" (does not match =~"^[a-z]{3}$") */
-```
+```