Add search and better filters in /issue-finder page

[saurabhdaware]

Currently, the issue-finder page can only filter based on one label. There should be a way to have multiple filters where you can say abelljs.org/issue-finder?label=enhancement,Hacktoberfest in the URL and it will return issues which have both of the labels on them.

Also, we can have a search bar that searches between the returned issues. We can search by a repository name, or in the title of the issues.

[rebelchris]

@saurabhdaware I would want to give this a try please

[saurabhdaware]

Sure @rebelchris Let me know if you need any help :D

[rebelchris]

@saurabhdaware Created PR #9 for the filter issue.