Added Updater to automatically perform OTA updates without user interaction.

DEPLOY.md

@@ -0,0 +1,9 @@
+# Deploying a new version
+
+* Update the OTA_VERSION in `include/config.h`, `include/config.sample.h`,
+  `data/_version.txt`, and `update.manifest`.
+* Commit the changes.
+* Tag the commit with the new version string.
+* Push everything.
+* Create theimages using `pio run` and `pio run -t buildfs`.
+* Upload `update.manifest`, `firmware.bin` and `spiffs.bin`.