fix: lc problem: No.0136 invalid code block label

No.0136.Single Number

Author: YangFong

solution/0100-0199/0136.Single Number/README.md

@@ -107,7 +107,7 @@ public:
 
 ### **Rust**
 
-```Rust
+```rust
 impl Solution {
     pub fn single_number(nums: Vec<i32>) -> i32 {
         let mut result = 0;

solution/0100-0199/0136.Single Number/README_EN.md

@@ -102,7 +102,7 @@ public:
 
 ### **Rust**
 
-```Rust
+```rust
 impl Solution {
     pub fn single_number(nums: Vec<i32>) -> i32 {
         let mut result = 0;