Make:Bluetooth copyedits

Example_4-3.ino

void unlockCharacteristicWritten(BLECentral& central, 
                                 BLECharacteristic& characteristic) {
    // central wrote new value to the unlock characteristic
    Serial.println(F("Unlock characteristic written"));
    openLock(characteristic.value(), characteristic.valueLength());
}

Example_6-1.ino

BLEPeripheral blePeripheral = BLEPeripheral(BLE_REQ, BLE_RDY, BLE_RST);
BLEService weatherService = BLEService("BBB0");
BLEFloatCharacteristic temperatureCharacteristic = 
    BLEFloatCharacteristic("BBB1", BLERead | BLENotify);
BLEDescriptor temperatureDescriptor = BLEDescriptor("2901", "Temp");
BLEFloatCharacteristic humidityCharacteristic = 
    BLEFloatCharacteristic("BBB2", BLERead | BLENotify);
BLEDescriptor humidityDescriptor = BLEDescriptor("2901", "Humidity");
BLEFloatCharacteristic pressureCharacteristic =
    BLEFloatCharacteristic("BBB3", BLERead | BLENotify);
BLEDescriptor pressureDescriptor = BLEDescriptor("2901", "Pressure");