The existing Bluetooth examples are split as:
1. examples/bluetooth/bluedroid - Bluedroid Host (BT + BLE) examples
a. examples/bluetooth/bluedroid/classic_bt - Classic BT examples
b. examples/bluetooth/bluedroid/ble - BLE examples
c. examples/bluetooth/bluedroid/coex - Classic BT and BLE coex examples
d. examples/bluetooth/bluedroid/hci - VHCI and HCI UART examples
i. Rename ble_adv to controller_vhci_ble_adv and move it in hci folder
2. examples/bluetooth/nimble - NimBLE BLE Host + NimBLE Mesh examples
3. examples/bluetooth/esp_ble_mesh - ESP BLE Mesh examples
4. Update documentation references
* Use "example" in all example function & variable names,
ie use i2c_example_xxx instead of i2c_xxx for example functions.
Closes#198https://github.com/espressif/esp-idf/issues/198
* Mark example functions, etc. static
* Replace uses of "test" & "demo" with "example"
* Split the UART example into two
* Rename "main" example files to end with "_main.c" for disambiguation
