Several commands of the documentation do not work any longer

[cryptax]

All of these in the documentation do not work:

• Batch mode: r2ai -c '-r act as a calculator' -c '3+3=?'
• Using r2pipe: #!pipe python -m r2ai.cli
• Define a macro command: '$r2ai=#!pipe python -m r2ai.cli
• https://infosec.exchange/@radareorg/111946255058894583 is lovely but does not work currently

NB. I'm working on a MR to fix the documentation.