add rustfmt.toml in runtime

runtime/rust-toolchain

@@ -0,0 +1 @@
+nightly

runtime/rustfmt.toml

@@ -0,0 +1,9 @@
+error_on_line_overflow = false
+format_strings = true
+normalize_comments = true
+imports_granularity = "Crate"
+reorder_modules = true
+# enum_discrim_align_threshold = 20
+use_try_shorthand = true
+wrap_comments = true
+edition = "2021"

runtime/src/container.rs

@@ -1,8 +1,9 @@
-use std::collections::HashMap;
-use std::sync::{Arc, Mutex};
+use std::{
+    collections::HashMap,
+    sync::{Arc, Mutex},
+};
 
-use leetcode::problems::Problem;
-use leetcode::solutions::Solution;
+use leetcode::{problems::Problem, solutions::Solution};
 
 #[derive(Default)]
 pub struct Container {

runtime/src/registration.rs

@@ -1,7 +1,6 @@
 use super::container::ContainerHandle;
 
-use leetcode::problems;
-use leetcode::solutions;
+use leetcode::{problems, solutions};
 
 pub fn register_all(handle: ContainerHandle) -> anyhow::Result<()> {
     handle.register_problem(|_| problems::two_sum::TwoSum)?;