Fixed typos, wrote a README, added LICENSE and CHANGELOG.md

README.md

@@ -1,2 +1,45 @@
 # go-scsupdate
 
+A tool to update the firmware of SCS PACTOR modems. Should run on most OSes.
+
+Author: Torsten Harenberg, DL1THM.
+
+
+Usage:
+
+```
+usage: go-scsupdate [-h|--help] [-s|--serialDevice "<value>"] [-b|--baudrate
+<integer>] -f|--file "<value>" [-d|--debug] [-n|--dryrun]
+[--force] [-t|--timeout <integer>]
+
+                    Update Firmware of SCS PACTOR modems
+
+Arguments:
+
+-h  --help          Print help information
+-s  --serialDevice  (optional) serial device the modem is attached to, e.g.
+/dev/ttyUSB0. If not set, go-scsupdate will search for
+SCS modems.
+-b  --baudrate      (optional, required when -s is set) sets the serial
+baudrate, e.g. 115200
+-f  --file          (required) the file to flash, e.g. profi41r.pro
+-d  --debug         (optional) enable debug logs
+-n  --dryrun        (optional) drying:  if set, modem will detected but no
+firmware being written
+--force         (optional) skip testing if firmware fits modem. Useful if
+the modem is bricked and you need to put it into BIOS
+mode. Read the manual!
+-t  --timeout       (optional) Sets the read and write timeout. Default: 70.
+If you have handshake problems, enlarge this values,
+especially for older modems.`
+```
+
+All options but -f, --file are optional. This requires that your OS is connected to the PACTOR modem through USB or Bluetooth (USB highly recommended!).
+
+If more than one, or if none, modem can be automatically detected, you can still select the device manually. 
+
+If your modem does not boot properly, the BIOS mode could help. See the handbook for details (you need to set a jumper on the PCB). Use the --force flag in this case, as the code cannot check which modem is attached.
+
+This whole project is derived from the C-based "scsupdate" by SCS, Hanau, Germany.
+
+A big thanks to the folks at SCS for their help and support making this possible.