Adds autocompletion support for zsh and bash

[laertispappas]

Address proposal in https://github.com/temporalio/proposals/blob/master/cli/003-cli-autocomplete.md

[CLAassistant]

All committers have signed the CLA.

[feedmeapples]

ty for the PR

[feedmeapples]

i'll send a copy to our new single binary cli (unless you send first) https://github.com/temporalio/cli

[laertispappas]

Hi @feedmeapples thank you,

What is the difference between tctl and cli?

[feedmeapples]

Hi @feedmeapples thank you,

What is the difference between tctl and cli?

just saw this .cli is going to be a replacement for tctl:

• it comes with similar Temporal management commands but with updated UX
• has a built-in temporal dev server and UI (via a new temporal server start-dev command)