Prepare private v0.20.1-alpha patron release

docs/README-PLAYTEST.txt

@@ -1,8 +1,8 @@
 straywild
-v0.19.0-alpha
-Alpha 0.19.0
+v0.20.1-alpha
+Alpha 0.20.1
 
-Thank you for trying this early private playtest.
+Thank you for supporting this private patron test release.
 
 straywild is an early multiplayer fishing game. This alpha includes local
 progression, player-hosted and dedicated multiplayer sessions, public room
@@ -83,6 +83,8 @@ FEATURES TO TRY
 - Fishing, net gathering, and beach digging
 - Equipment and consumable use from the hotbar
 - Fishing Shop sell tray, wallet updates, and persistent upgrades
+- Portable RV homes, multiplayer visits, RV storage, and the early decor
+  purchasing and placement prototype
 - Seeded generated worlds and the authored starter-island layout
 - Generated beaches, ponds, lakes, complete rivers, denser forests, varied
   elevation, and closed coastal cliffs
@@ -117,5 +119,6 @@ KNOWN ALPHA LIMITATIONS
   networks may prevent some players from joining.
 - Multiplayer, dedicated-server deployment, UI, and balance are still alpha.
 - Some fish and character artwork remains temporary.
+- RV exteriors and decor use temporary prototype geometry and presentation.
 - There is no installer or automatic updater.
 - Windows builds are unsigned.