os.mkfs() replaced with os.fsformat()

os.mkfs() has been replaced with os.fsformat()

Link explaining the replacement details:
https://forum.pycom.io/topic/3351/new-development-firmware-release-v1-19-0-b1/2

Issue: https://forum.pycom.io/topic/5606/what-happened-to-pin_deepsleep_wakeup/9

content/gettingstarted/programming/first-project.md

@@ -118,5 +118,5 @@ If you need to remove files from your device you have two options, either connec
 ```python
 
 import os
-os.mkfs('/flash')
+os.fsformat('/flash')
 ```

content/gettingstarted/programming/safeboot.md

@@ -35,7 +35,7 @@ If problems occur within the filesystem or you wish to factory reset your module
 ```python
 
 >>> import os
->>> os.mkfs('/flash')
+>>> os.fsformat('flash')
 ```
 
 {{% hint style="danger" %}}
@@ -59,4 +59,3 @@ A hard reset is the same as performing a power cycle to the device. In order to
 >>> import machine
 >>> machine.reset()
 ```
-