Added HRT example and NVS examples
Added example for the High Resolution Timer (esp_timer)
- shows difference between basic periodic and one-shot timers
Added examples for Non-Volatile Storage (nvs_rw_value, nvs_rw_blob)
- nvs_rw_value => shows how read and write a single integer value using NVS
- nvs_rw_blob => shows how to read and write a single integer value and a blob (binary large object)