fix naming

snippets/truncate-string.md

@@ -0,0 +1,10 @@
+### Truncate a String
+
+Determine if the string's `length` is greater than `num`.
+Return the string truncated to the desired length, with `...` appended to the end or the original string.
+
+```js
+const truncateString = (str, num) =>
+  str.length > num ? str.slice(0, num > 3 ? num - 3 : num) + '...' : str;
+// truncate('boomerang', 7) -> 'boom...'
+```