cue: fix typos in the Hid function documentation

Closes #2847 as merged as of commit 127554b.

Signed-off-by: kharf <kevinfritz210@gmail.com>
Change-Id: I2ddb2b25831377e0734a70c29b0015c0587332c3
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1177403
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@gmail.com>
Reviewed-by: Roger Peppe <rogpeppe@gmail.com>

cue/path.go

@@ -467,9 +467,9 @@ func isHiddenOrDefinition(s string) bool {
 	return strings.HasPrefix(s, "#") || strings.HasPrefix(s, "_")
 }
 
-// Hid returns a selector for a hidden field. It panics is pkg is empty.
+// Hid returns a selector for a hidden field. It panics if pkg is empty.
 // Hidden fields are scoped by package, and pkg indicates for which package
-// the hidden field must apply.For anonymous packages, it must be set to "_".
+// the hidden field must apply. For anonymous packages, it must be set to "_".
 func Hid(name, pkg string) Selector {
 	if !ast.IsValidIdent(name) {
 		panic(fmt.Sprintf("invalid identifier %s", name))