Add note about using Node 12

[nichhk]

Fixes #1205

• Up to date with dev branch
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• Peer reviewed and approved

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[ardada2468]

Got a couple of npm errors using npm 12

• It had to do with the post install script in package.json

• "postinstall": "sh -c \"are-you-es5 check -r . | tail -n 2 | head -n 1 > ./node_modules_non_es5 \""

• This might might work on unix based machines, but it will not work on windows.

• As a temporary fix I just replaced the string above with a empty string and it was able to install all packages and load up the development server locally.

• I think we need to create a new issue for this, and also edit the the documentations temporarily for windows users, and instruct them to replace the following line to empty string

• This is the error I got
  NPM Error.txt

• This is the package.json file that got rid of the errors.
  PackageJson.txt

[nichhk]

Thanks for taking a look Arnav! Good to know about the issue with the postinstall script. I dug into it a bit, and it looks like this was used to identify some issues with the site on IE11. It seems like the postinstall was just used once to update some dependencies.

So I think we can safely delete the postinstall line entirely. But I agree that that change should be tracked in a separate issue. Can you open the issue please? Is there anything blocking this PR?