Updates to templates README and js template package

[thilgen]

Context

1. examples/templates/README.md
   • Clarified the manual copy instructions
   • Fixed an error in the supplied cp command
2. examples/templates/js/package.json
   • Attempting to run npm install with a freshly copied version of the js template results in an error

   % npm install
   npm WARN workspaces vanilla-template1 in filter set, but no workspace folder present
   npm WARN deprecated puppeteer@7.1.0: < 19.2.0 is no longer supported
   npm ERR! code 1
   ...
   

   • Fix is to bump up the version of puppeteer to 14.3.0
   • Note: puppeteer:14.3.0 looks to have been in use for all the examples since Handsontable:12.1.0

How has this been tested?

• Tested locally

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature or improvement (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Additional language file or change to the existing one (translations)

Related issue(s):

1. n/a

Affected project(s):

• handsontable
• @handsontable/angular
• @handsontable/react
• @handsontable/vue
• @handsontable/vue3

Checklist:

• I have reviewed the guidelines about Contributing to Handsontable and I confirm that my code follows the code style of this project.
• I have signed the Contributor License Agreement
• My change requires a change to the documentation.

[adrianszymanski89]

Hi @thilgen

Once again. Thank you for your contribution. We will review your PR as soon as possible