Rails.threadsafe! mode is deprecated, Update Docs

[gaurish]

Rails.threadsafe! mode is deprecated, update docs to reflect this.

[robin850]

Thank you @gaurish!

[arunagw]

Hey @gaurish would you like to get access to docrails repo?
If you want to contribute more in docs 😄. With access you can directly push to docrails for guides changes.

[gaurish]

@arunagw Yes, please 👍

[fxn]

I believe this edit should read "If you are running in a multi-threaded environment", the fact that Rails is multi-thread by default is not very relevant.

It was before, with the previous wording people only enabled threading if they needed it.

[robin850]

@fxn : Sorry ; I merged it a bit too quickly.

@gaurish : Would you mind committing the proposed changed by @fxn to docrails ? If you can't, I can do it. :-)

[fxn]

@robin850 no prob at all! ❤️

[gaurish]

@robin850
Done via https://github.com/rails/docrails/commit/b91d76131b2dd5fbd4d73f6e1e925c9e6f9880f6

[robin850]

Thank you @gaurish! :-)