load game data from file; dedupe getElement calls

script.js

@@ -29,6 +29,8 @@ async function run() {
         pageButton.addEventListener('touchend', pagination);
     }
 
+    const gameDataInput = document.getElementById("game-data");
+
     function new_game() {
         load_default_game_data();
         // we don't need to look at the default game data, so skip ahead to the image page
@@ -36,7 +38,7 @@ async function run() {
     }
 
     function clear_game() {
-        document.getElementById("game-data").innerHTML = "";
+        gameDataInput.innerHTML = "";
     }
 
     let new_game_button = document.getElementById("new");
@@ -61,6 +63,12 @@ async function run() {
         }
     }
 
+    document.getElementById("game").addEventListener("change", function() {
+        readFile(this, function (e) {
+            gameDataInput.innerHTML = e.target.result;
+        }, "text");
+    });
+
     const preview = document.getElementById("preview");
     preview.style.display = "none";