fix: update documentation for flags

Signed-off-by: 1998-felix <felix.gateru@gmail.com>

README.md

@@ -21,9 +21,9 @@ Flags:
   -c, --content-format int    Content format (default 50)
   -h, --help                  help for coap-cli
   -H, --host string           Host (default "localhost")
-  -k, --keep-alive uint       Keep alive interval (default 60)
+  -k, --keep-alive uint       Send a ping after interval seconds of inactivity. If not specified (or 0), keep-alive is disabled (default).
   -m, --max-retries uint32    Max retries for keep alive (default 10)
-  -O, --options stringArray   Options
+  -O, --options num,text      Add option num with contents of text to the request. If the text begins with 0x, then the hex text (two [0-9a-f] per byte) is converted to binary data.
   -p, --port string           Port (default "5683")
   -v, --verbose               Verbose output
   -d, --data string           Data(default "") - only available for put, post and delete commands

cmd/main.go

@@ -83,8 +83,8 @@ func main() {
 	rootCmd.PersistentFlags().StringVarP(&port, "port", "p", "5683", "Port")
 	rootCmd.PersistentFlags().StringVarP(&auth, "auth", "a", "", "Auth")
 	rootCmd.PersistentFlags().IntVarP(&contentFormat, "content-format", "c", 50, "Content format")
-	rootCmd.PersistentFlags().StringArrayVarP(&options, "options", "O", []string{}, "Options")
-	rootCmd.PersistentFlags().Uint64VarP(&keepAlive, "keep-alive", "k", 60, "Keep alive interval")
+	rootCmd.PersistentFlags().StringArrayVarP(&options, "options", "O", []string{}, "Add option num with contents of text to the request. If the text begins with 0x, then the hex text (two [0-9a-f] per byte) is converted to binary data.")
+	rootCmd.PersistentFlags().Uint64VarP(&keepAlive, "keep-alive", "k", 0, "Send a ping after interval seconds of inactivity. If not specified (or 0), keep-alive is disabled (default).")
 	rootCmd.PersistentFlags().Uint32VarP(&maxRetries, "max-retries", "m", 10, "Max retries for keep alive")
 	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "Verbose output")