message: docs: reword the FAQ regarding table changes
  So we stop confusing people that thinks we do DDL.
  Fix
diff: @@ -170,8 +170,8 @@ You can override this path using the ``SUPERSET_HOME`` environment variable.
  Another work around is to change where superset stores the sqlite database by adding ``SQLALCHEMY_DATABASE_URI = 'sqlite:////new/location/superset.db'`` in superset_config.py (create the file if needed), then adding the directory where superset_config.py lives to PYTHONPATH environment variable (e.g. ``export PYTHONPATH=/opt/logs/sandbox/airbnb/``).
  -How do I add new columns to an existing table
  ----------------------------------------------
  +What if the table schema changed?
  +---------------------------------
  Table schemas evolve, and Superset needs to reflect that. It's pretty common
  in the life cycle of a dashboard to want to add a new dimension or metric.
  