Add instructions to install xcode command line tools on MacOS

[mpeterdev]

Prerequisites

• I'm using the latest version of near-sdk-js.
• I have tried to start with a fresh project and reproduce the defect with minimal code changes.
• I have read the console error messages carefully (if applicable).

Description

My teammate encountered issues building contracts which yielded cryptic errors. In the end, the issue was discovered to be that he did not have xcode command line tools installed which provides some build tool dependencies

The command to install is xcode-select --install and if they are already installed then it is a no-op with a response of

xcode-select: note: Command line tools are already installed. Use "Software Update" in System Settings or the softwareupdate command line interface to install updates

Ideally, this could be checked on package install. Otherwise, documenting in the prerequisites section of the README is a good start

Reproducible demo

No response

Steps to reproduce

N/A

Expected behavior

N/A

Actual behavior

N/A

Your environment

No response

Self-service

• I'd be willing to fix this bug myself.

[pavelisnear]

Another possible way to resolve this issue is to run softwareupdate --install-rosetta in the terminal.
https://support.apple.com/en-us/102527