docs: add OpenSSF Best Practices badge to README

Project registered at bestpractices.dev (ID: 13100) with 100%
passing score across all 67 criteria.

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

README.md

@@ -8,6 +8,7 @@
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://github.com/patchloom/patchloom-vscode/blob/main/LICENSE)
 [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/patchloom/patchloom-vscode/badge)](https://securityscorecards.dev/viewer/?uri=github.com/patchloom/patchloom-vscode)
 [![FOSSA Status](https://img.shields.io/badge/license%20scan-FOSSA-blue)](https://app.fossa.com/projects/git%2Bgithub.com%2Fpatchloom%2Fpatchloom-vscode)
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/13100/badge)](https://www.bestpractices.dev/projects/13100)
 
 The official VS Code extension for [Patchloom](https://github.com/patchloom/patchloom). Set up your workspace for AI agent workflows in seconds: detect the CLI, generate agent rules, configure MCP servers, and run structured file operations from the command palette.