add type hint to avoid reflection

src/clj_figlet/core.clj

@@ -102,7 +102,7 @@
   [flf ^Character c & [initial-output]]
   (let [output-lines      (or initial-output (get-initial-output-lines flf))
         char-lines        (get-in flf [:chars c])
-        hardblank    (get-in flf [:header :hardblank-str])]
+        ^String hardblank (get-in flf [:header :hardblank-str])]
     (if char-lines
       (map
         (fn [^String char-line ^String output-line]