docs(readme): 致谢改为平实感谢，去掉「欠人情」的债务叙事

原段落把作者写成亏欠方（「这个项目欠它们一份很大的人情」/ "exists very much in
their debt"），并把 HMCL / PCL2 称作 "old-timers"。两者都是 GPL-3.0 开源项目，
阅读与借鉴本就在许可之内，不需要愧疚来偿付。

- 债务词全部移除：欠 / 人情 / debt / owe / old-timers / enormous amount
- 保留感谢本身，改成「它们做得久 + 本项目从中受益」两句话
- 中文补一次断行以保持 ≤100 显示列

README.md

@@ -185,10 +185,8 @@ Minimum baseline: **Windows 10**; Windows 8.1 / 8 / 7 are not supported.
   `zip` / `flate2` / `tar` (MIT / Apache-2.0). The allow-list cargo-deny enforces is in `deny.toml`;
   GPL-family dependencies may not enter the main line.
 
-Thanks to [HMCL](https://github.com/HMCL-dev/HMCL) and
+Thanks to [HMCL](https://github.com/HMCL-dev/HMCL) and [PCL2](https://github.com/Meloong-Git/PCL)
-[PCL2](https://github.com/Meloong-Git/PCL) (both GPL-3.0) — those two old-timers have been riding
+(both GPL-3.0). They have been with the vast majority of Minecraft players for years, and this
-along with the overwhelming majority of Minecraft players for years now. This launcher learned an
+project has benefited a great deal from their design choices and implementation details.
-enormous amount from them about how a launcher should feel and how it should work, and it exists
-very much in their debt.
 
 Not affiliated with Mojang or Microsoft.

README.zh-CN.md

@@ -162,7 +162,7 @@ cargo build --release                                  # 三个 bin 都落在 ta
   （MIT / Apache-2.0）。cargo-deny 强制执行的白名单在 `deny.toml`；GPL 系依赖不得进主干。
 
 感谢 [HMCL](https://github.com/HMCL-dev/HMCL) 和 [PCL2](https://github.com/Meloong-Git/PCL)
-（均 GPL-3.0）——这两位陪着绝大多数 MC 玩家走了好多年的老前辈。启动器该是什么手感、该怎么把一件
+（均 GPL-3.0）。这两款启动器陪着绝大多数 MC 玩家走了很多年，
-事做顺，我们是从它们身上学的；这个项目欠它们一份很大的人情。
+本项目在设计取舍与实现细节上都从中受益良多。
 
 与 Mojang、Microsoft 无关联。