Add watch task

run with `cargo make watch`, might need `cargo-watch` to be installed.

Makefile.toml

@@ -33,6 +33,12 @@ description = "Build, and create wasms"
 workspace = false
 dependencies = ["build", "create_wasm"]
 
+[tasks.watch]
+description = "watch code, build, and create wasms"
+workspace = false
+dependencies = ["build", "create_wasm"]
+watch = { ignore_pattern="pkg/*" }
+
 [tasks.all_release]
 description = "Build, and create wasms, with the --release flag"
 workspace = false