Add Batch Install Plugins installation instructions to various plugins and filters

- Updated README files for the following plugins to include installation instructions using Batch Install Plugins:
  - deep-dive
  - export_to_docx
  - export_to_excel
  - flash-card
  - infographic
  - smart-mind-map
  - async-context-compression
  - chat-session-mapping-filter
  - folder-memory
  - github_copilot_sdk_files_filter
  - markdown_normalizer
  - github-copilot-sdk
  - iflow-sdk-pipe
  - openwebui-skills-manager
  - smart-mind-map-tool

- Added important notes regarding the removal of the official OpenWebUI Community version before installation.

plugins/actions/export_to_excel/README.md

@@ -8,6 +8,19 @@
 
 Export chat history to an Excel (.xlsx) file directly from the chat interface.
 
+## Install with Batch Install Plugins
+
+If you already use [Batch Install Plugins from GitHub](https://github.com/Fu-Jie/openwebui-extensions/tree/main/plugins/tools/batch-install-plugins), you can install or update this plugin with:
+
+```text
+Install plugin from Fu-Jie/openwebui-extensions
+```
+
+When the selection dialog opens, search for this plugin, check it, and continue.
+
+> [!IMPORTANT]
+> If the official OpenWebUI Community version is already installed, remove it first. After that, Batch Install Plugins can keep this plugin updated in future runs.
+
 ## 🔥 What's New in v0.3.6
 
 - **OpenWebUI-Style Theme**: Modern dark header (#1f2937) with light gray zebra striping for better readability.