Add trigger-tree documentation telemetry plugin

[Hedde]

Adds trigger-tree to the Documentation category as an external GitHub source.

trigger-tree records which documentation Claude Code discovers during normal repository work and presents the local event data as a live dashboard, heat/cold maps, health diagnostics, and evidence-backed router suggestions. Runtime telemetry stays local and uses no model tokens or network calls.

Changes

• Register Hedde/trigger_tree as an external GitHub plugin source
• Add the plugin to the English and Chinese Documentation lists
• Include release, author, license, homepage, repository, keyword, and tag metadata

Validation

• jq empty .claude-plugin/marketplace.json
• Unique trigger-tree plugin-name check
• External source repository field check
• git diff --check
• Upstream repository CI: Python 3.10–3.13 compatibility, Linux/macOS/Windows tests, Ruff, Black, ShellCheck, plugin validation, CodeQL, dependency review, and 100% Python coverage