change default for 'autodescribe' to 'on'

This was discussed two years ago then nothing happened.  Make
autodescribe for feedback when moving the cursor to pick something
default to on instead of off.

src/options.c

@@ -78,7 +78,7 @@ static struct Bool_Opt {
 #else
     { "asksavedisk", (boolean *) 0, FALSE, SET_IN_FILE },
 #endif
-    { "autodescribe", &iflags.autodescribe, FALSE, SET_IN_GAME },
+    { "autodescribe", &iflags.autodescribe, TRUE, SET_IN_GAME },
     { "autodig", &flags.autodig, FALSE, SET_IN_GAME },
     { "autoopen", &flags.autoopen, TRUE, SET_IN_GAME },
     { "autopickup", &flags.pickup, TRUE, SET_IN_GAME },