Make list type selector case sensitive (#2418)

* Make list type selector case sensitive

* Create .changeset/quiet-lamps-smile.md

Author: simurai

.changeset/quiet-lamps-smile.md

@@ -0,0 +1,5 @@
+---
+"@primer/css": patch
+---
+
+Make list type selector case sensitive

src/markdown/lists.scss

@@ -14,19 +14,19 @@
     }
   }
 
-  ol[type='a'] {
+  ol[type='a s'] {
     list-style-type: lower-alpha;
   }
 
-  ol[type='A'] {
+  ol[type='A s'] {
     list-style-type: upper-alpha;
   }
 
-  ol[type='i'] {
+  ol[type='i s'] {
     list-style-type: lower-roman;
   }
 
-  ol[type='I'] {
+  ol[type='I s'] {
     list-style-type: upper-roman;
   }