backwards: Share reading-material with phone and tablet

hosts/backwards/modules/syncthing/default.nix

@@ -34,6 +34,7 @@ in
         devices = {
           phone.id = config.lib.syncthing.phone;
           pinwheel.id = config.lib.syncthing.pinwheel;
+          tablet.id = config.lib.syncthing.tablet;
         };
 
         folders = {
@@ -84,6 +85,20 @@ in
             };
           };
 
+          "reading-material" = {
+            path = "/home/alex/sync/reading-material";
+            devices = [
+              "phone"
+              "tablet"
+            ];
+            versioning = {
+              type = "staggered";
+              params = {
+                maxAge = "2592000"; # 30 days
+              };
+            };
+          };
+
           "phone-gps" = {
             path = "/home/alex/sync/phone-gps";
             devices = [ "phone" ];