Update README showing macro usage.

Author: aentinger

Diff for: README.md

@@ -24,7 +24,7 @@ Example:
 ```C++
 int i = 1;
 float pi = 3.1459;
-Debug.print(DBG_VERBOSE, "i = %d, pi = %f", i, pi);
+DEBUG_VERBOSE("i = %d, pi = %f", i, pi);
 ```
 **Note**: The output of floating point numbers (`%f`) does NOT work on [ArduinoCore-avr](https://github.com/arduino/ArduinoCore-avr).
 
@@ -43,7 +43,7 @@ Parameter debug_level in order of lowest to highest priority are : `DBG_NONE`, `
 Return type: void.
 
 Example:
-```
+```C++
 Debug.setDebugLevel(DBG_VERBOSE);
 ```
 ### Debug.setDebugOutputStream(Stream * stream) :
@@ -52,7 +52,7 @@ By default, Output Stream is Serial. In advanced cases other objects could be ot
 Return type: void.
 
 Example:
-```
+```C++
 SoftwareSerial mySerial(10, 11); // RX, TX
 Debug.setDebugOutputStream(&mySerial);
 ```
@@ -63,9 +63,9 @@ By default, printing timestamp is off, unless turned on using this function call
 Return type: void.
 
 Example:
-```
+```C++
 Debug.timestampOn();
-Debug.print(DBG_VERBOSE, "i = %d", i); //Output looks like : [ 21007 ] i = 21 
+DBG_VERBOSE("i = %d", i); //Output looks like : [ 21007 ] i = 21
 ```
 
 ### Debug.timestampOff() :
@@ -74,9 +74,9 @@ Calling this function switches off the timestamp in the `Debug.print()` function
 Return type: void.
 
 Example:
-```
+```C++
 Debug.timestampOff();
-Debug.print(DBG_VERBOSE, "i = %d", i); //Output looks like : i = 21 
+DEBUG_VERBOSE("i = %d", i); //Output looks like : i = 21
 ```
 
 ### Debug.newlineOn() :
@@ -85,7 +85,7 @@ By default, a newline is sent
 Return type: void.
 
 Example:
-```
+```C++
 Debug.newlineOn();
 ```
 
@@ -95,7 +95,7 @@ By default a newline is sent. Call this to shut that functionality off.
 Return type: void.
 
 Example:
-```
+```C++
 Debug.timestampOff();
 ```
 
@@ -106,8 +106,8 @@ This function prints the message if parameter `debug_level` in the `Debug.print(
 Return type: void.
 
 Example:
-```
+```C++
 Debug.setDebugLevel(DBG_VERBOSE);
 int i = 0;
-Debug.print(DBG_VERBOSE, "DBG_VERBOSE i = %d", i);
+DEBUG_VERBOSE("DBG_VERBOSE i = %d", i);
 ```