chore: add VS Code auto-format and pre-commit hook

- Enable format on save for Rust files
- Configure rust-analyzer to use rustfmt
- Add pre-commit hook to auto-format Rust code before commits
- Ensure consistent line endings (LF) and trim trailing whitespace

Author: Mohammod Al Amin Ashik

.vscode/settings.json

@@ -0,0 +1,13 @@
+{
+  "[rust]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "rust-lang.rust-analyzer"
+  },
+  "rust-analyzer.rustfmt.extraArgs": [
+    "+nightly"
+  ],
+  "files.eol": "\n",
+  "files.insertFinalNewline": true,
+  "files.trimTrailingWhitespace": true,
+  "editor.formatOnSave": true
+}