Basic Hello World Example

Other examples are located in: ~/home/.platformio/packages/framework-espidf/examples

1. File-> Open Folder -> ~/home/.platformio/packages/framework-espidfexamples/espidf-hello-world
   (also can be downloaded from github:
   https://github.com/platformio/platform-espressif32/blob/master/examples/espidf-hello-world/src/hello_world_main.c
2. Open and edit the platformio.ini file update the default monitor speed to 115200 in platformio.ini file, and also delete the other boards which are not used.
   The example platformio.ini from SkeletonHuzzah32 can also be used:
   https://github.com/ucb-ee192/SkeletonHuzzah32/blob/main/platformio.ini

[env:featheresp32]
platform = espressif32
framework = espidf
board = featheresp32
monitor_speed = 115200

3. build (takes about 6 minutes)
4. check baud rate in platformio.ini: (monitor_speed = 115200)
5. upload
6. works in putty terminal