v0.12.1

Update options and usage messages as below (#36)

$ .\expect.exe
Expect-lua v0.12.1-windows-amd64 with go1.20.14
Usage of .\expect.exe:
  -D    print debug information
  -compile executable-name
        compile executable with <script>.lua embedded; script is not executed
  -e code
        execute code
  -nocolor
        disable color

• Print logo only when no arguments are given, and hide the option -nologo from the usage.
• Rename -printembederror to -D for debug-print
• Modify the description of the usage of -compile
• Add -nocolor as boolean option and hide -color option from the usage, because -color auto was same as -color always and does not need to be string-option
  Thanks to @misha-franz