Fix copy'n'paste spelling mistakes. (#20)

Author: aentinger

examples/Advanced/DAC_One_Channel/DAC_One_Channel.ino

@@ -27,7 +27,7 @@ void dac_output_sq(AdvancedDAC &dac_out) {
             buf.data()[i] =  (i % 2 == 0) ? 0: 0xfff;
         }
 
-        // Writethe buffer to DAC.
+        // Write the buffer to DAC.
         dac_out.write(buf);
     }
 }

examples/Advanced/DAC_Sine_wave/DAC_Sine_wave.ino

@@ -32,7 +32,7 @@ void loop() {
             buf[i] =  lut[lut_offs % lut_size];
         }
 
-        // Writethe buffer to DAC.
+        // Write the buffer to DAC.
         dac1.write(buf);
     }
 }

examples/Advanced/DAC_Two_Channels/DAC_Two_Channels.ino

@@ -33,7 +33,7 @@ void dac_output_sq(AdvancedDAC &dac_out) {
           buf.data()[i] =  (i % 2 == 0) ? 0: 0xfff;
         }
 
-        // Writethe buffer to DAC.
+        // Write the buffer to DAC.
         dac_out.write(buf);
     }
 }