docs: add OOpenWebUI official newsletter featured recognition to Smart Mind Map, Markdown Normalizer, and Prompt Plus (#52)

* Initial plan

* docs: add OpenWebUI official newsletter featured recognition

- Add newsletter featured callout to Smart Mind Map README.md, README_CN.md, and docs
- Add newsletter featured callout to Markdown Normalizer README.md, README_CN.md, and docs
- Add newsletter featured badge to Prompt Plus in root README.md and README_CN.md
- Reference both newsletters: Jan 28, 2026 and Feb 3, 2026

Co-authored-by: Fu-Jie <33599649+Fu-Jie@users.noreply.github.com>

* docs: fix newsletter links to match actual featured issue per plugin

- Smart Mind Map: link only to Feb 3, 2026 (second newsletter)
- Markdown Normalizer: link only to Jan 28, 2026 (first newsletter)
- Prompt Plus (root READMEs): already correct, no change needed

Co-authored-by: Fu-Jie <33599649+Fu-Jie@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Fu-Jie <33599649+Fu-Jie@users.noreply.github.com>

docs/plugins/actions/smart-mind-map.md

@@ -5,6 +5,8 @@
 
 Intelligently analyzes text content and generates interactive mind maps for better visualization and understanding.
 
+> 🏆 **Featured by OpenWebUI Official** — Recommended in the official OpenWebUI Community Newsletter: [February 3, 2026](https://openwebui.com/blog/open-webui-community-newsletter-february-3rd-2026)
+
 ---
 
 ## Overview

docs/plugins/actions/smart-mind-map.zh.md

@@ -5,6 +5,8 @@
 
 智能分析文本内容，生成交互式思维导图，帮助你更直观地理解信息结构。
 
+> 🏆 **OpenWebUI 官方推荐** — 获得 OpenWebUI 社区 Newsletter 官方推荐：[2026 年 2 月 3 日](https://openwebui.com/blog/open-webui-community-newsletter-february-3rd-2026)
+
 ---
 
 ## 概览

docs/plugins/filters/markdown_normalizer.md

@@ -4,6 +4,8 @@
 
 A content normalizer filter for Open WebUI that fixes common Markdown formatting issues in LLM outputs. It ensures that code blocks, LaTeX formulas, Mermaid diagrams, and other Markdown elements are rendered correctly.
 
+> 🏆 **Featured by OpenWebUI Official** — Recommended in the official OpenWebUI Community Newsletter: [January 28, 2026](https://openwebui.com/blog/newsletter-january-28-2026)
+
 ## 🔥 What's New in v1.2.7
 
 * **LaTeX Formula Protection**: Enhanced escape character cleaning to protect LaTeX commands like `\times`, `\nu`, and `\theta` from being corrupted.

docs/plugins/filters/markdown_normalizer.zh.md

@@ -4,6 +4,8 @@
 
 这是一个用于 Open WebUI 的内容格式化过滤器，旨在修复 LLM 输出中常见的 Markdown 格式问题。它能确保代码块、LaTeX 公式、Mermaid 图表和其他 Markdown 元素被正确渲染。
 
+> 🏆 **OpenWebUI 官方推荐** — 获得 OpenWebUI 社区 Newsletter 官方推荐：[2026 年 1 月 28 日](https://openwebui.com/blog/newsletter-january-28-2026)
+
 ## 🔥 最新更新 v1.2.7
 
 * **LaTeX 公式保护**: 增强了转义字符清理逻辑，自动保护 `$ $` 或 `$$ $$` 内的 LaTeX 命令（如 `\times`、`\nu`、`\theta`），防止渲染失效。