Fix changelog wording: "merged" → "migrated content from"

One of the 5 legacy docs (plugins.md) was superseded rather than
merged, making "merged" inaccurate.

Author: AnExiledDev

.devcontainer/CHANGELOG.md

@@ -11,7 +11,7 @@
 - Updated prerequisites and installation docs to support all DevContainer clients (VS Code, CLI, JetBrains Gateway, DevPod, Codespaces)
 - Added tabbed client-specific instructions on the installation page
 - Added dedicated port forwarding reference page covering VS Code auto-detect, devcontainer-bridge, and SSH tunneling
-- **Ported `.devcontainer/docs/` to docs site** — merged 5 legacy reference docs into the Starlight documentation site:
+- **Ported `.devcontainer/docs/` to docs site** — migrated content from 5 legacy reference docs into the Starlight documentation site:
   - New **Keybindings** page (Customization) — VS Code/Claude Code shortcut conflicts and resolution options
   - New **Troubleshooting** page (Reference) — 12+ problem/solution entries for build, auth, plugins, and performance issues
   - New **Optional Features** page (Customization) — mcp-qdrant vector memory setup guide