Enable all platforms by default

This can be done now since all platforms validate their settings
Worst case, the platforms can just be disabled again

src/defaultconfig.toml

@@ -1,26 +1,28 @@
 debug= false
 
+[steamgrid_db]
+
 [origin]
-enabled = false
+enabled = true
 
 [gog]
-enabled = false
+enabled = true
 create_symlinks = true
 
 [epic_games]
-enabled = false
+enabled = true
 create_symlinks = true
 
 [uplay]
-enabled = false
+enabled = true
 
 [legendary]
-enabled = false
+enabled = true
 
 [steam]
 
 [itch]
-enabled = false
+enabled = true
 create_symlinks = true
 
 [steamgrid_db]
@@ -28,4 +30,4 @@ enabled = true
 prefer_animated = false
 
 [lutris]
-enabled = true
+enabled = true