docs: add VPS.Town as sponsor to all README (OpenListTeam#1842)

Co-authored-by: XZB-1248 <i@1248.ink>

Author: XZB-1248

README.md

@@ -128,6 +128,10 @@ N/A (to be rebuilt)
 
 Please refer to [*Discussions*](https://github.com/OpenListTeam/OpenList/discussions) for raising general questions, ***Issues* is for bug reports and feature requests only.**
 
+## Sponsor
+
+[![VPS.Town](https://vps.town/static/images/sponsor.png)](https://vps.town "VPS.Town - Trust, Effortlessly. Your Cloud, Reimagined.")
+
 ## License
 
 The `OpenList` is open-source software licensed under the [AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.txt) license.

README_cn.md

@@ -128,6 +128,10 @@ N/A（待重建）
 
 如有一般性问题请前往 [*Discussions*](https://github.com/OpenListTeam/OpenList/discussions) 讨论区，***Issues* 仅用于错误报告和功能请求。**
 
+## 赞助
+
+[![VPS.Town](https://vps.town/static/images/sponsor.png)](https://vps.town "VPS.Town - Trust, Effortlessly. Your Cloud, Reimagined.")
+
 ## 许可证
 
 `OpenList` 是基于 [AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.txt) 许可证的开源软件。

README_ja.md

@@ -128,6 +128,10 @@ N/A（再構築中）
 
 一般的な質問は [*Discussions*](https://github.com/OpenListTeam/OpenList/discussions) をご利用ください。***Issues* はバグ報告と機能リクエスト専用です。**
 
+## スポンサー
+
+[![VPS.Town](https://vps.town/static/images/sponsor.png)](https://vps.town "VPS.Town - Trust, Effortlessly. Your Cloud, Reimagined.")
+
 ## ライセンス
 
 「OpenList」は [AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.txt) ライセンスの下で公開されているオープンソースソフトウェアです。

README_nl.md

@@ -128,6 +128,10 @@ N.v.t. (wordt opnieuw opgebouwd)
 
 Stel algemene vragen in [*Discussions*](https://github.com/OpenListTeam/OpenList/discussions), ***Issues* zijn alleen voor bugmeldingen en feature requests.**
 
+## Sponsoren
+
+[![VPS.Town](https://vps.town/static/images/sponsor.png)](https://vps.town "VPS.Town - Trust, Effortlessly. Your Cloud, Reimagined.")
+
 ## Licentie
 
 `OpenList` is open-source software onder de [AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.txt) licentie.