added external pump control

lib/WiFiManagerParameters/DoubleParameter.h

@@ -0,0 +1,21 @@
+#pragma once
+#include <WiFiManager.h>
+
+class DoubleParameter : public WiFiManagerParameter {
+public:
+  DoubleParameter(const char* id, const char* label, double value, const uint8_t length = 10) : WiFiManagerParameter("") {
+    init(id, label, String(value, length - 1).c_str(), length, "", WFM_LABEL_DEFAULT);
+  }
+
+  double getValue() {
+    return atof(WiFiManagerParameter::getValue());
+  }
+
+  void setValue(double value, int length) {
+    WiFiManagerParameter::setValue(String(value, length - 1).c_str(), length);
+  }
+
+  void setValue(double value) {
+    setValue(value, getValueLength());
+  }
+};