Have a user-friendly project inventory

## Feature

Right now the only way to see projects on Code.mil is to look at the `code.json` file. I would like to have a user-friendly view of the projects in that inventory for anyone to peruse. The Code.gov team [has something like this](https://code.gov/#!/browse-projects), but I'm not sure if it is reusable, and we don't necessarily need it to look like that.

Start by reviewing the existing code.json inventory and the Code.gov browse-projects example linked in the issue. Define a user-friendly project browsing view, including its scope and presentation, and consider whether the referenced Code.gov approach is reusable; done means users can peruse the inventory without opening code.json.

Written by the indexing model from the issue text.