Replace non-breaking spaces with normal spaces in the README

Looks better in IDEA's editor.

Signed-off-by: Graham <gpe@openrs2.dev>

README.md

@@ -26,12 +26,12 @@ beneath the root of the repository), in the following structure:
 ```
 nonfree
 └── lib
-    ├── jaggl.pack200
+    ├── jaggl.pack200
-    ├── loader_gl.jar
+    ├── loader_gl.jar
-    ├── loader.jar
+    ├── loader.jar
-    ├── runescape_gl.pack200
+    ├── runescape_gl.pack200
-    ├── runescape.jar
+    ├── runescape.jar
-    └── unpackclass.pack
+    └── unpackclass.pack
 ```
 
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