changed header to .hpp to use strings as identifiers

client/client/lib/espnow/src/espnow.cpp

 #include <esp_now.h>
 #include "WiFi.h"
-#include "espnow.h"
+#include "espnow.hpp"
 
 uint8_t BROADCAST_MAC[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; //probably shouldn't be defined here, works for now
 esp_now_peer_info_t hostInfo;

client/client/lib/espnow/src/espnow.h

-#define NUM_SENSORS 10
-
-// I originally wanted to define the mac addresses here, but i got a "multiple definition" error?
-typedef struct dataMessage{
-    int identifiers[NUM_SENSORS];
-    float values[NUM_SENSORS];
-}dataMessage;
-
-int send_data(dataMessage data);
-
-int espnow_setup();
-

client/client/src/main.cpp

 #include <Arduino.h>
-#include "espnow.h"
+#include "espnow.hpp"
 
 void setup() {