added protobuf and badger deps and wrote proto file for calendar event

flake.nix

@@ -61,6 +61,9 @@
               gcc
               go_1_23
               nixpkgs-fmt
+	      protobuf
+	      badger
+	      protoc-gen-go
             ];
             env = {
               CGO_ENABLED = "1";

proto/calendar.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package calendar;
+
+option go_package = "calendar";
+
+message Event {
+  string title = 1;
+  string description = 2;
+  int32 year = 3;
+  int32 month = 4;
+  int32 day = 5;
+  int32 start_hour = 6;
+  int32 end_hour = 7;
+}