Add Wenlan to CLI tools

[7xuanlu]

What changed

• Add Wenlan to the open-source CLI section.
• Use the plain-text icon because Wenlan maintains Markdown pages.
• Include the current Apache-2.0 license and Rust implementation.

Why

Wenlan is a local source-backed AI knowledge base for agents. It maintains cited Markdown pages and exposes them through CLI, MCP, and HTTP interfaces, which fits this list's knowledge-management scope and CLI category.

Impact

Readers looking for local, command-line knowledge-management tools can discover Wenlan alongside the existing plain-text CLI entries.

Checks

• Confirmed there is no existing Wenlan entry or pull request.
• Confirmed the repository is active, Apache-2.0 licensed, and implemented in Rust.
• Confirmed the public GitHub link returns HTTP 200.
• Confirmed the diff is exactly one README insertion and passes git diff --check.
• Checked the contribution format, icon rules, category, and active-maintenance requirement.