Update Application Page: Add search bar functionality

Iteration #1 (closed): Update of the Application Page.

Requirement for search bar functionality to search for application by keyword/name. The about.gitlab.com website already has search functionality embedded (see attached image, so it would be great to have something similar on this page.

Action Items:

• Add search bar
• Display results on page rather than than a pop up box with the search results, like the current website
• Placement of search bar should be beneath the line below the text: Every application that supports Git will work with GitLab. Below are some of the applications we wanted to highlight. You can use the GitLab API to add support for GitLab. Please file a merge request to add a new application to the list.
• Similar to other search bars on about.gitlab.com, could this search bar please also have the opacified font written within it: Search for an application by name… (again, similar to the attached image)
• Could the search box please also have be the same width as the line above it and centred in the page.