docs: add Univer Office plugin

[DR-Univer]

🚀 Contribution Description

Adds Univer Office, an OpenClaw plugin that connects agents to a collaborative Univer Workspace for creating and reviewing office artifacts. The project supports spreadsheets, documents, slides, boards, PDFs, relational tables, self-hosted deployment, real-time collaboration, and import/export workflows.

Disclosure: I am affiliated with the project.

📋 Checklist

• Correct Section: Added to Plugins.
• Formatting: Uses the required [Name](Link) - Description. format.
• Alphabetical Order: Placed between TweetClaw and Webhook Bridge.
• No Duplicates: Searched the README for existing Univer entries.
• Valid Link: Verified the public repository URL.

🔗 Resource Details

• Name: Univer Office
• URL: https://github.com/dream-num/openclaw-univer-office
• Category: Plugins

Validation

• npm run lint:local