Add preventDefault to voter lookup submit

[SchaeStewart]

Description

Add e.preventDefault to voter lookup form submit.

By default HTML forms will try to submit data to the server, and refresh the page. (You don't really see this behavior in most modern development anymore, but in ye-olden-days of the web this was standard). You can prevent the the form from submitting data to the server and refreshing the page by using e.preventDefault, where e is the form submit event in your handler function

MDN for prevent default: https://developer.mozilla.org/en-US/docs/Web/API/Event/preventDefault

Related Issue

188

How Has This Been Tested?

Tested locally

Screenshots (if appropriate):

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed.

PS: Whoever setup the dev environment for this project was an idiot ;)