update doc for BOARD name, add note for udev on Linux

examples/device/99-tinyusb.rules

@@ -0,0 +1,14 @@
+# Copy this file to the location of your distribution's udev rules, for example on Ubuntu:
+#   sudo cp 99-tinyusb.rules /etc/udev/rules.d/
+# Then reload udev configuration by executing:
+#   sudo udevadm control --reload-rules
+#   sudo udevadm trigger
+
+# Check SUBSYSTEM
+SUBSYSTEMS=="hidraw", KERNEL=="hidraw*", MODE="0666", GROUP="dialout"
+
+# Rule applies to all TinyUSB example
+ATTRS{idVendor}=="cafe", MODE="0666", GROUP="dialout"
+
+# Rule to blacklist TinyUSB example from being manipulated by ModemManager.
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="cafe", ENV{ID_MM_DEVICE_IGNORE}="1"

examples/device/webusb_serial/src/main.c

@@ -23,6 +23,26 @@
  *
  */
 
+/* This example demonstrates WebUSB as web serial with browser with WebUSB support (e.g Chrome).
+ * After enumerated successfully, browser will pop-up notification
+ * with URL to landing page, click on it to test
+ *  - Click "Connect" and select device, When connected the on-board LED will litted up.
+ *  - Any charters received from either webusb/Serial will be echo back to webusb and Serial
+ *
+ * Note:
+ * - The WebUSB landing page notification is currently disabled in Chrome
+ * on Windows due to Chromium issue 656702 (https://crbug.com/656702). You have to
+ * go to landing page (below) to test
+ *
+ * - On Windows 7 and prior: You need to use Zadig tool to manually bind the
+ * WebUSB interface with the WinUSB driver for Chrome to access. From windows 8 and 10, this
+ * is done automatically by firmware.
+ *
+ * - On Linux/macOS, udev permission may need to be updated by
+ *   - copying '/examples/device/99-tinyusb.rules' file to /etc/udev/rules.d/ then
+ *   - run 'sudo udevadm control --reload-rules && sudo udevadm trigger'
+ */
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>