Remove spreadsheet from tracking and add .gitignore

- Remove Raleigh jobs FIRE ALARM INFORMATION.xlsx from git
- Add .gitignore to prevent tracking spreadsheets and other artifacts

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

.gitignore

@@ -0,0 +1,17 @@
+# Spreadsheets
+*.xlsx
+*.xls
+*.csv
+*.ods
+
+# Virtual environment
+.venv/
+
+# Python
+__pycache__/
+*.py[cod]
+*.egg-info/
+
+# IDE
+.idea/
+.vscode/