Cryptol REPL should say how to get help when it starts

[brianhuffman]

When you start ghci, it tells noobs how to get help:

GHCi, version 8.6.5: http://www.haskell.org/ghc/  :? for help

But cryptol doesn't give any such hints:

┏━╸┏━┓╻ ╻┏━┓╺┳╸┏━┓╻
┃  ┣┳┛┗┳┛┣━┛ ┃ ┃ ┃┃
┗━╸╹┗╸ ╹ ╹   ╹ ┗━┛┗━╸
version 2.7.1 (ede8c3f, modified)

Loading module Cryptol
Cryptol>

I'm thinking about the times I've accidentally started vim, couldn't figure out how to quit the program, and then had to open another terminal to kill the process.

Maybe we should add a hint to the startup message about typing :? for help.

[brianhuffman]

Time for bike-shedding! Should we just add the help hint to the version line, like this:

┏━╸┏━┓╻ ╻┏━┓╺┳╸┏━┓╻
┃  ┣┳┛┗┳┛┣━┛ ┃ ┃ ┃┃
┗━╸╹┗╸ ╹ ╹   ╹ ┗━┛┗━╸
version 2.7.1 (ede8c3f) :? for help

Loading module Cryptol
Cryptol>

or put an additional line with a URL and the help hint like this:

┏━╸┏━┓╻ ╻┏━┓╺┳╸┏━┓╻
┃  ┣┳┛┗┳┛┣━┛ ┃ ┃ ┃┃
┗━╸╹┗╸ ╹ ╹   ╹ ┗━┛┗━╸
version 2.7.1 (ede8c3f)
https://cryptol.net  :? for help

Loading module Cryptol
Cryptol>

or maybe something else entirely?

[atomb]

My favorite is your second example above, @brianhuffman.

[brianhuffman]

Fixed by #657 (revision dd6d8d2).