doc/ref/spec.md: fix typo
Fixes #187
Change-Id: I252819c2f5e5f0420e0c5bdb7f713415045207f2
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/4120
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/doc/ref/spec.md b/doc/ref/spec.md
index 2fe4864..9eb080e 100644
--- a/doc/ref/spec.md
+++ b/doc/ref/spec.md
@@ -448,7 +448,7 @@
`#` string_lit `#` .
simple_string_lit = `"` { unicode_value | interpolation } `"` .
-simple_bytes_lit = `"` { unicode_value | interpolation | byte_value } `"` .
+simple_bytes_lit = `'` { unicode_value | interpolation | byte_value } `'` .
multiline_string_lit = `"""` newline
{ unicode_value | interpolation | newline }
newline `"""` .