refactor: move firmware workspace under firmware

firmware/libs/kaptan-config-derive/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "kaptan-config-derive"
+edition.workspace = true
+license.workspace = true
+rust-version.workspace = true
+version.workspace = true
+
+[lib]
+proc-macro = true
+
+[lints]
+workspace = true
+
+[dependencies]
+proc-macro2 = "1"
+quote = "1"
+syn = { version = "2", features = ["full"] }
+
+[dev-dependencies]
+kaptan-config = { path = "../kaptan-config" }
+trybuild = "1"