Fix: markdownlint MD012/MD019 errors in build-pattern-conversion-plan.md

- Removed extra blank lines at end of file to resolve MD012 (no-multiple-blanks)
- Standardized heading spacing to resolve MD019 (no-multiple-space-atx)
- Stripped trailing whitespace and ensured file ends with a single newline

All changes maintain content integrity and bring the file into full markdownlint compliance.

scripts/format-markdown.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+
+# format-markdown.sh
+# Author: Matthew Raymer
+# Date: 2025-07-09
+# Description: Format markdown files to comply with project markdown ruleset
+
+set -e
+
+if [ $# -eq 0 ]; then
+  echo "Usage: $0 <file-or-directory> [more files...]"
+  exit 1
+fi
+
+for target in "$@"; do
+  if [ -d "$target" ]; then
+    files=$(find "$target" -type f -name "*.md")
+  else
+    files="$target"
+  fi
+  for file in $files; do
+    # Remove trailing spaces
+    sed -i 's/[[:space:]]*$//' "$file"
+    # Remove multiple consecutive blank lines
+    awk 'NF{blank=0} !NF{blank++} blank<2' "$file" > "$file.tmp" && mv "$file.tmp" "$file"
+    # Ensure file ends with a single newline
+    awk '1; END{if (NR && $0!="") print ""}' "$file" > "$file.tmp" && mv "$file.tmp" "$file"
+    # Optionally run markdownlint (requires npx and markdownlint-cli)
+    if command -v npx >/dev/null 2>&1; then
+      npx markdownlint "$file"
+    else
+      echo "npx/markdownlint not found, skipping lint check for $file"
+    fi
+  done
+done
+
+echo "Markdown formatting complete."