Adding telnet for remote debugging purpose

LibreMetric.ino

@@ -1,3 +1,6 @@
+// global config
+
+#include "config.h"
 
 //################# LIBRARIES ##########################
 #include <ESP8266WiFi.h>
@@ -8,6 +11,8 @@
 #include <Adafruit_GFX.h>
 #include <Max72xxPanel.h>
 #include <time.h>
+#include "d_helper.h"
+
 
 //################# DISPLAY CONNECTIONS ################
 // LED Matrix Pin -> ESP8266 Pin
@@ -53,7 +58,13 @@ void setup() {
   Serial.println(F("WiFi connected..."));
   Serial.println(WiFi.localIP());
   configTime(timezone * 3600, dstOffset * 3600, ntpServer); // First sync of time with (S)NTP
-  
+
+#ifdef DEBUG_TELNET
+  // Start the Telnet server
+  telnetServer.begin();
+  telnetServer.setNoDelay(true);
+#endif
+
 //----------------------------------------------------------------------
   server.begin();
   Serial.println(F("Webserver started..."));
@@ -73,6 +84,10 @@ void setup() {
 }
 
 void loop() {
+#ifdef DEBUG_TELNET
+  // Handle Telnet connection for debugging
+  handleTelnet();
+#endif
   server.handleClient();
   matrix.fillScreen(LOW);
   time_t now = time(nullptr);