Update 07.UsingTextFiles.md

Added tutorial stuff for checking if a text file exists

Author: spark-the-dragon

assets/content/cookbook/Advanced/07.UsingTextFiles.md

@@ -1,6 +1,6 @@
-[tags]: / "advanced,txt,hscript"
+[tags]: / "advanced,txt,haxe"
 
-# Using Text Files
+# Text Files
 
 While not used much by Friday Night Funkin' (in exception to `introText.txt`), the ability to read and save to text files may be useful for some mods. 
 
@@ -58,4 +58,34 @@ class Tutorial extends Song {
 }
 ```
 
+## Checking if a text file exists
+
+You may want to check if a text file exists before trying to read or write to it. To do this, we will still be using the same import used to save a text file, `funkin.util.FileUtil`, and will do the following:
+
+```haxe
+import funkin.play.song.Song;
+import funkin.util.FileUtil; // Required module to save text files
+
+class Tutorial extends Song {
+    public function new() 
+    {
+        super("bopeebo"); // This must be the song name just lowercased
+    }
+    
+    override public function onCreate():Void // This will be called upon the game starting
+    {
+        super.onCreate();
+        var checkForFile = FileUtil.pathExists(Assets.getPath(Paths.txt('Player'))); // We will be checking in the data folder of the mod this script is running in
+        if (checkForFile == false) // This means the file does NOT exist
+        {
+            trace('File "Player.txt" does not exist in ' + Assets.getPath(Paths.txt('Player'))); // Along with printing the result, this will also tell you the path it expected the file to be in.
+        }
+        if (checkForFile == true) // This means the file does exist
+        {
+            trace('File "Player.txt" does exist in ' + Assets.getPath(Paths.txt('Player')));
+        }
+    }
+}
+```
+
 > Author: [Spark the Dragon](https://github.com/spark-the-dragon)