📝 Add some jsDocs to getElementType function

I always forget what this ElementType refers too, no more.

Author: vhoyer

Diff for: src/utils/getElementType.ts

@@ -3,6 +3,13 @@ import type { AST } from "vue-eslint-parser";
 import getElementAttributeValue from "./getElementAttributeValue";
 import makeKebabCase from "./makeKebabCase";
 
+/**
+ * Returns a kebab-normalized string representing the element node name
+ * or, if the `is` attribute is a string, its value if present.
+ * @example <div is="foo-bar"> => "foo-bar"
+ * @example <foo-bar> => "foo-bar"
+ * @example <div> => "div"
+ */
 function getElementType(node: AST.VElement) {
   let is = getElementAttributeValue(node, "is");