fix: Exclude .vscode directory from markdown linting

This prevents linting third-party dependencies in the .vscode/build/_deps/ directory.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

Author: tgd1975

Makefile

@@ -96,7 +96,7 @@ format:
 
 # Fix markdown linting issues (requires markdownlint-cli2)
 lint-markdown:
-	npx markdownlint-cli2 "**/*.md" "#node_modules" "#.pio" "#build"
+	npx markdownlint-cli2 "**/*.md" "#node_modules" "#.pio" "#build" "#.vscode"
 	@echo "Markdown linting complete"
 
 # Clean test artifacts