add initial marp implementation with sample content and build configuration

node_modules/speech-rule-engine/mjs/enrich_mathml/enrich_case.js

@@ -0,0 +1,9 @@
+export function getCase(node) {
+    for (let i = 0, enrich; (enrich = factory[i]); i++) {
+        if (enrich.test(node)) {
+            return enrich.constr(node);
+        }
+    }
+    return null;
+}
+export const factory = [];