Add serial interface for initial configuratio (#664)

* add SerialReader

* fix SerialReader

* add config upload script

* add serial command to print ip address

* update serial script to save configuration and reset after upload

* fix updater

* fix updater

* serial config fixes

* serial config fixes

* fix wifi static example configuration

* add readme for sendcfg.py

scripts/sendcfg/example_configurations/m5stack-w5500.json

@@ -0,0 +1,4 @@
+{
+  "hostname": "nuki-atom-w5500",
+  "nwhw": "3"
+}