feat: add astrbot-core rust project

rust/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "astrbot-core"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

rust/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}