change(bsec): use -2.2 K default offset

Documentation/card10-cfg.rst

@@ -61,5 +61,5 @@ Option name        Type       Description
 ------------------ ---------- -----------
 ``bsec_debug``     Boolean    Turn on debug output of the BSEC system. Prints each meaurement on the console.
 ------------------ ---------- -----------
-``bsec_offset``    Integer    Temperature offset in .1 K. Example: Set to `-14` if temperature reads 1.4 "C" to high.
+``bsec_offset``    Integer    Temperature offset in .1 K. Example: Set to `-14` if temperature reads 1.4 "C" to high. Default: -2.2 K (appropriate for a card10 without a case, connected to USB and with BLE active in vertical orientation).
 ================== ========== ===========

epicardium/modules/bsec.c

@@ -387,7 +387,7 @@ int bsec_activate(void)
 	debug = config_get_boolean_with_default("bsec_debug", false);
 
 	float temperature_offset =
-		config_get_integer_with_default("bsec_offset", 0) / 10.;
+		config_get_integer_with_default("bsec_offset", -22) / 10.;
 	if (temperature_offset != 0.0) {
 		LOG_INFO(
 			"besec",