docs(contributing): install and use yarn 1

[PixnBits]

Description

Currently $ npm install yarn installs v2

Motivation

this project uses yarn v1 for installing

Test Conditions

none

Types of changes

Check boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (adding or updating documentation)
• Dependency update
• Security update

Checklist

Check boxes that apply:

• My code follows the code style of this project.
• My change requires a change to the documentation and I have updated the documentation accordingly.
• These changes should be applied to a maintenance branch.
• I have added the Apache 2.0 license header to any new files created.

[10xLaCroixDrinker]

https://github.com/americanexpress/one-app-cli/pull/504/files/3ed27ab5f6f372146af2cf9024a757bd8f653a2d#r1134373356

[github-actions]

This pull request is stale because it has been open 30 days with no activity.