Initial BLS data reference and DC/MD/VA unemployment dashboard

Includes:
- API v1/v2 documentation, endpoints, request/response schemas
- Complete survey catalog (60 surveys, live-fetched from API)
- Series ID decode tables: LAUS, CES, SM, QCEW, OES, JOLTS, CPI, PPI
- QCEW quarterly (47 fields) and annual (43 fields) CSV schemas
- dc_md_va_unemployment.py: pulls 16 LAUS series for DC/MD/VA + DC MSA
- Example API response and 5-year CSV output

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config.example.py

@@ -0,0 +1,13 @@
+# BLS API Configuration
+# ----------------------
+# 1. Register for a free API key at: https://data.bls.gov/registrationEngine/
+#    Required fields: first name, last name, organization, email address.
+#    Your key will be emailed within a few minutes.
+#
+# 2. Copy this file to config.py:
+#       cp config.example.py config.py
+#
+# 3. Paste your key below and save.
+
+BLS_API_KEY = "YOUR_KEY_HERE"
+BLS_API_BASE = "https://api.bls.gov/publicAPI/v2"