Consider adding warning to readme

[RX14]

See: https://github.com/crystal-lang/crystal/issues/5128

[oprypin]

Heck, maybe add a warning at the start of each icr run

[greyblake]

LOL :) I thought we get this complaint much earlier.

Not everyone reads README carefully, so I am for adding the warnings to the icr so it prints it on every start. The message should warn about the following:

• Network operations
• File operations
• Random numbers
• Time / Time.now
• Anything else?

[martinos]

In the current README the explanation is in the "How does it work?" section. Personally I skip reading such sections because when I start using a library I don't care that much about the implementation details.

I think that adding a big warning near the beginning of the README and/or when irc is launched would do it. This warning would tell the user that each time that a command is run, the program gets recompiled and rerun and its internal state will get lost and recalculated.

@greyblake, I think we could add Time.now to your list.

[greyblake]

Maybe we can display the message when icr is running first time by the user?

[oprypin]

Just do it every time but add a flag to disable the warning and then a user can add the flag in a bashrc alias

[RX14]

Or do it like GNU parallel's citation notice: you run parallel --citation and it silences the message forever.