README: link StarRupture to its Steam store page

starrupture.com is a parked domain, not official; there is no standalone
official site, so the game's home is its Steam page. The AppID there (1631270)
matches the constant save discovery uses.

Author: agentical-info

README.md

@@ -3,7 +3,7 @@
 Adds a **CONTINUE** entry to the main menu that loads your most recent save in one click. Vanilla needs three
 screens to resume — `LOAD GAME` → pick a world → pick a save; Continue collapses that to one button, focused by
 default, so pressing Enter at the main menu drops you straight back into your last game. A mod for the PC game
-StarRupture.
+[StarRupture](https://store.steampowered.com/app/1631270/StarRupture/).
 
 - **Target:** Game client
 - **Built for:** Early Access build `0.2.8.121391-S` — a later game update may require an update.