Issue #3133: Use placeholder attribute for placeholder text.

[jenlampton]

Fixes #3133

Summary

• Switched placeholder text from value attribute to placeholder attribute on input element.

Please double-check that:

• All changes were made in CoffeeScript files, not JavaScript files.
• You used Grunt to build the JavaScript files and tested them locally.
• You've updated both the jQuery and Prototype versions.
• You haven't manually updated the version number in package.json.
• N/A If necessary, you've updated the documentation.

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References

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• Use placeholder attribute on input elements for placeholder text (instead of value attribute) #3133

[jenlampton]

The command npm install failed with the error The package-lock.json file was created with an old version of npm and a handful of deprecations, so I was not able to use Grunt to build the JavaScript files.

To test locally, I modified the chosen.jquery.js file directly since the change was very simple.

If someone else can get grunt working with the latest version of chosen, I could use some help with the build process for this PR.