Add documentation to usb_reset_interface.h

Author: will-v-pi

src/common/pico_usb_reset_interface_headers/include/pico/usb_reset_interface.h

@@ -8,9 +8,24 @@
 #define _PICO_USB_RESET_INTERFACE_H
 
 /** \file usb_reset_interface.h
- *  \defgroup pico_usb_reset_interface_headers pico_usb_reset_interface_headers
+ *  \defgroup pico_usb_reset_interface pico_usb_reset_interface
  *
- * \brief Definition for the reset interface that may be exposed by the pico_usb_reset_interface library
+ * \brief Functionality to enable the RP-series microcontroller to be reset over the USB interface.
+ *
+ * This library can be used to enable the RP-series microcontroller to be reset over the USB interface.
+ *
+ * This functionality is included by default when using the `pico_stdio_usb` library and not using TinyUSB directly.
+ *
+ * To add this functionality to a project using TinyUSB directly, you need to:
+ * 1. Link the pico_usb_reset_interface library, and include the `pico/usb_reset_interface.h` header file where needed.
+ * 2. Define PICO_STDIO_USB_ENABLE_RESET_VIA_VENDOR_INTERFACE=1
+ * 3. Add `TUD_RPI_RESET_DESCRIPTOR(<ITF_NUM>, <STR_IDX>)` to your USB descriptors (length is `TUD_RPI_RESET_DESC_LEN`)
+ * 4. Check if your project has an existing `usbd_app_driver_get_cb` function:
+ *    - If it does, you need to add the `_resetd_driver` to the drivers returned
+ *    - If it does not, and you aren't using the `pico_stdio_usb` library, you need to define `PICO_STDIO_USB_RESET_INCLUDE_APP_DRIVER_CB=1`
+ * 5. Check if your project has an existing Microsoft OS 2.0 Descriptor:
+ *    - If it does, you need to add the Function Subset header `RPI_RESET_MS_OS_20_DESCRIPTOR(<ITF_NUM>)` to your Microsoft OS 2.0 Descriptor (length is `RPI_RESET_MS_OS_20_DESC_LEN`)
+ *    - If it does not, you need to define `PICO_STDIO_USB_RESET_INTERFACE_SUPPORT_MS_OS_20_DESCRIPTOR=1` and `PICO_STDIO_USB_RESET_INTERFACE_MS_OS_20_DESCRIPTOR_ITF=<ITF_NUM>`
  */
 
 // These defines are used by picotool