fix(glossy): use codepoints (not bytes!) in article code

Fixes [#18](https://github.com/swaits/typst-collection/issues/18)

glossy/tests/utf-handling/test.typ

@@ -0,0 +1,20 @@
+#import "/lib.typ":*
+
+#set text(lang: "cs", region: "CZ")
+
+#show: init-glossary.with(yaml("glossary.yml"))
+#glossary(ignore-case: true)
+
+#line(length: 20em)
+
+@čr
+
+@cab
+
+@coo
+
+@cuckoo
+
+@delta
+
+@dal