Want to start fixing New Hampshire’s housing shortage? Start with ‘starter’ homes. That was the message of Americans for Prosperity’s recent “Boom or Bust: New Hampshire’s Real Estate Market” gathering in Goffstown. Lawmakers and economic experts argued for a state strategy of making it easier for developers to build in-demand single-family homes. State Reps. Joe Alexander (R-Goffstown) and Mark Warden (R-Manchester) laid the groundwork this pas…