Update CLI --help output in README

Author: bessman

README.md

@@ -45,24 +45,23 @@ Mcbootflash can be used as both a command-line application and a library.
 
 ```shellsession
 $ mcbootflash --help
-usage: mcbootflash [-h] -p PORT -b BAUDRATE [-t TIMEOUT] [-c] [-r] [-v] [-q] [--version] hexfile
+usage: mcbootflash [-h] -p PORT -b BAUDRATE [--timeout TIMEOUT] [--checksum] [--reset] [--debug] [--quiet] [--version] hexfile
 
-Flash firmware over serial connection to a device running Microchip's 16-bit bootloader.
+mcbootflash is a tool for flashing firmware to 16-bit Microchip MCUs and DSCs from the PIC24 and dsPIC33 device families, which are running a bootloader generated by the MPLAB Code Configurator tool.
 
 positional arguments:
-  hexfile               a HEX file containing application firmware
+  hexfile               an Intel HEX file containing application firmware
 
 options:
   -h, --help            show this help message and exit
-  -p PORT, --port PORT  serial port connected to the device you want to flash
-  -b BAUDRATE, --baudrate BAUDRATE
+  -p, --port PORT       serial port connected to the device you want to flash
+  -b, --baudrate BAUDRATE
                         symbol rate of device's serial bus
-  -t TIMEOUT, --timeout TIMEOUT
-                        try to read data from the bus for this many seconds before giving up
-  -c, --checksum        verify flashed data by checksumming after write
-  -r, --reset           reset device after flashing is complete
-  -v, --verbose         print debug messages
-  -q, --quiet           suppress output
+  --timeout TIMEOUT     try to read data from the bus for this many seconds before giving up
+  --checksum            verify flashed data by checksumming after write
+  --reset               reset device after flashing is complete
+  --debug               print debug messages
+  --quiet               suppress output
   --version             show program's version number and exit
 ```