Add decoder conf for Thomson kinetic doorbell (#2940)

conf/Thomson-doorbell.conf

@@ -0,0 +1,25 @@
+# Thomson doorbell
+#
+# old model with 23 bits: https://www.hornbach.de/p/p/4618196/
+# new model with 25 bits: https://www.amazon.de/dp/B09P5Y4G1B/
+#
+# This decoder reads button presses from handles harvesting energy while you press it (they have no battery).
+# A newly bought button sends roughly four complete rows before energy runs out.
+# An older button sends one complete row until it finally falls out (I have one outside working for many years).
+#
+# Due to its short pulses sampling rate must be 1M.
+# You should listen at 433.8MHz to receive a stable signal.
+# rtl_433 -R 0 -c conf/Thomson-doorbell.conf -f 433.8M -s 1024k
+#
+# Analyzed by @TheChatty #2940
+
+decoder {
+        name        = Thomson-Doorbell,
+        modulation  = OOK_PWM,
+        short       = 50,
+        long        = 150,
+        gap         = 200,
+        reset       = 3000,
+        bits       >= 23,
+        unique,
+}