feat: extism works

__wasm/extism/extism_plugin/src/lib.rs

@@ -0,0 +1,23 @@
+use extism_pdk::*;
+use serde::Serialize;
+
+const VOWELS: &[char] = &['a', 'A', 'e', 'E', 'i', 'I', 'o', 'O', 'u', 'U'];
+
+#[derive(Serialize)]
+struct TestOutput {
+    pub count: i32,
+}
+
+#[plugin_fn]
+pub fn count_vowels(input: String) -> FnResult<Json<TestOutput>> {
+    let mut count = 0;
+    for ch in input.chars() {
+        if VOWELS.contains(&ch) {
+            count += 1;
+        }
+    }
+
+    let output = TestOutput { count };
+    Ok(Json(output))
+}
+