Publish Vulpes Preview 15 sources for desktop, Android and Tundra

Share Gaia assets and adapters, keep private profiles and development documents local, and update both public READMEs.

gaia/apps/wallpaper/build/tablet/wallpapers/list.json

@@ -0,0 +1,11 @@
+[
+  "default.jpg",
+  "FXOS_Rocky_Hills_L.jpg",
+  "FXOS_Violet_Daisy_L.jpg",
+  "FXOS_Calm_Beach_L.jpg",
+  "FXOS_Dynamic_Sunset_L.jpg",  
+  "FXOS_Mysterious_Seascape_L.jpg",
+  "FXOS_leap.jpg",
+  "FXOS_stance.jpg",
+  "FXOS_bolt.jpg"
+]