Update README to reflect removal of HTTP server mode

- Remove obsolete Server Mode section (removed in 3014cf9)
- Update plugin installation commands to correct syntax
- Remove startServer from programmatic usage (no longer exported)
- Remove BrowserServer API section (class removed)
- Add close tool to MCP tools reference
- Sync plugin.json version to 0.2.13-pre.0

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "browse",
   "description": "Browser automation and image processing tools for Claude Code using Playwright WebKit",
-  "version": "0.2.10",
+  "version": "0.2.13-pre.0",
   "author": {
     "name": "aladac",
     "url": "https://github.com/aladac"