docs: clarify troubleshooting step

Author: ThisAMJ

doc/web/index.html

@@ -223,7 +223,7 @@ <h1>Troubleshooting</h1>
                 Keep in mind that this mod is a compilation of <b>dirty hacks</b> that this poor 2011 engine was not prepared for. 
                 In case the game crashes or bugs itself in an unexplainable way, try one of these things:
                 <ul>
-                    <li>Launch the <b>main game</b>, then the mod.</li>
+                    <li>Make sure you've launched the <b>main game</b> at least once, then launch the mod.</li>
                     <li>(D3D error) Temporarily add <code>-safe</code> to the launch options in the mod's Steam properties.</li>
                     <li>(Manifest file error) Install the mod on the <b>same drive</b> as the main game,
                         or <a target="_blank" href="https://discord.com/channels/146404426746167296/1085725696665595934/1144043513265274920" title="P2SR Discord help FAQ">edit the files.</a></li>