feat: add new zellij_version thingy

src/main.zig

@@ -26,6 +26,8 @@ test {
 ///     zz.createPlugin(@This());
 /// }
 ///
+/// pub const zellij_version = "0.33.0";
+///
 /// pub fn init() void {}
 /// pub fn update(event: zz.Event) void {
 ///     var event = zz.getEvent(gpa.allocator()) catch return;
@@ -56,6 +58,10 @@ pub fn createPlugin(comptime Plugin: type) void {
         export fn update() void {
             Plugin.update();
         }
+
+        export fn plugin_version() void {
+            std.io.getStdOut().writeAll(Plugin.zellij_version ++ "\n") catch unreachable;
+        }
     };
 }