2.1 - WiFi scanning and text scrolling

New features

• Wifi scanning by @DaveDavenport - the WiFi network in the configuration page can now be selected from a list of available networks.
• experimental text scroller feature (demo video), usable via HTTP API as well as MQTT, see UsersManual for details.

Maintenance highlights

• added a PlatformIO target to merge binaries, and documentation to flash the merged binary from esptool-js. For OTA updates, use the regular firmware file.
• fixed a bug preventing manual time setting when MQTT is enabled

Note: Updating from a firmware version < 2.0, via OTA or otherwise, will reset your settings.

Full Changelog: 2.0...2.1