docs: update Codes/README.md — document _DEBUG guard as recommended approach (#1517)

* docs: update Codes/README.md to document _DEBUG guard usage

The repo's .vscode/tasks.json passes -D_DEBUG in both g++ (Windows)
and clang++ (macOS) build tasks, and c_cpp_properties.json also
defines _DEBUG for IntelliSense on both platforms.

Update the README to document this cross-platform _DEBUG guard as
the recommended approach alongside the existing _WIN32 example.

Ref: #1516 (review comment r3106352313)

* docs: simplify — just replace _WIN32 with _DEBUG and note its origin

Revert the previous over-engineered change. Keep it minimal:
- Replace #ifdef _WIN32 with #ifdef _DEBUG
- Add one line explaining where _DEBUG is defined

* docs: minimal update — use _DEBUG guard and note its origin

Replace _WIN32 with _DEBUG in both code examples, add one-line
explanation of where _DEBUG is defined. No other structural changes.

* fix: restore original text, only change _WIN32→_DEBUG and intro line

Address review: revert all unintended changes (Chinese quote escaping,
trailing newline, structural changes). Only 3 lines differ from master:
- Line 50: intro text updated to mention _DEBUG origin
- Line 53: #ifdef _WIN32 → #ifdef _DEBUG
- Line 63: #ifdef _WIN32 → #ifdef _DEBUG

* docs: _DEBUG by hand

Update README.md

* fix: 虽然最好有个空格，但是得到准许前还是不修改比较好

Update README.md

* docs: rust->Rust

* docs: 加个结尾句号

Update Codes/README.md

---------

Co-authored-by: gh-pr-review[bot] <268385713+gh-pr-review[bot]@users.noreply.github.com>
Co-authored-by: gh-pr-review <github-gh-pr-review@cmail.letmefly.xyz>

Author: gh-pr-review[bot]

Codes/README.md

@@ -47,20 +47,22 @@ LeetCode很多题不需要写头文件、main函数等，因此在本地编写
 
 如何解决这个问题呢？只需引入```Codes```下的```_[1,2]toVector.h```即可。
 
-如果你使用的是Windows，引入方式：
+引入方式：
 
 ```cpp
-#ifdef _WIN32
+#ifdef _DEBUG
 #include "_[1,2]toVector.h"
 #endif
 ```
 
+（其中`_DEBUG`由[`c_cpp_properties.json`](https://github.com/LetMeFly666/LeetCode/blob/c3797c6100e0581d2658b6e334aa1d639d4a8f8c/.vscode/c_cpp_properties.json#L25)(IDE插件用)和[`.vscode/tasks.json`](https://github.com/LetMeFly666/LeetCode/blob/c3797c6100e0581d2658b6e334aa1d639d4a8f8c/.vscode/tasks.json#L34)(编译用)中的`-D_DEBUG`编译参数定义）
+
 然后就可以编写LeetCode的代码了。
 
 ```_[1,2]toVector.h```中包含了很多LeetCode中常用的数据结构，如果想在本地调试，可以在文件尾部加上代码如：
 
 ```cpp
-#ifdef _WIN32
+#ifdef _DEBUG
 int main() {
     string s;
     while (cin >> s) {
@@ -76,4 +78,4 @@ int main() {
 
 ## 其他文件
 
-`cargo.lock`、`cargo.toml`、`lib.rs`都是rust所需
+`cargo.lock`、`cargo.toml`、`lib.rs`都是Rust所需。