initialize core structure

Signed-off-by: Onur Özkan <work@onurozkan.dev>

kaptan-runtime/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "kaptan-runtime"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+rust-version.workspace = true
+version.workspace = true