Optimize build assets (#6)

* feat: handle Dev and Prod modes

* fix: remove useles variable override

* refactor: ssr entry point fn

* feat: pass Mode from server to client

* feat: enable read file from out/client dir

* feat: load manifest data from server side

* feat: remap manifest when loaded

* feat: load correct bundle server side

* doc: update README.md

* doc: update tutorial

crates/tuono_lib/src/mode.rs

@@ -0,0 +1,10 @@
+use once_cell::sync::OnceCell;
+use serde::Serialize;
+
+#[derive(Debug, PartialEq, Eq, Serialize, Clone, Copy)]
+pub enum Mode {
+    Dev,
+    Prod,
+}
+
+pub static GLOBAL_MODE: OnceCell<Mode> = OnceCell::new();