Initial TODOs

[chl33]

• WifiManager: Captive portal when logged-in to AP mode
• HA app example
  • Publish some data
  • Register some variable for HA discovery
• Adafruit.io mode for MQTT. The trick here is that a VariableGroup will need to send a MQTT message per variable rather than json for all variables.
• SSL support for MQTT. Might need compile flags to enable.