update and clean up

[mckelveygreg]

• [x] update styles to use styled-components
• [x] use styled-components globalStyles
• [x] use gatsby-image for all plausible images
• [x] load json with graphQL?
• [x] add offline support
• [x] add Gatsby SEO component
• [x] update package.json

[mckelveygreg]

Project Postmortem:

• With the current design in place, it is very hard to turn the ship around without re-designing the whole site
• GraphQL is easier to use if all of your data is pipelined through it, otherwise it doesn't make as much sense
• In order to load all of the current JSON data through graphQL, it would take a little bit of massaging, especially to get images working. Things could be integrated closer, but the current system does what it is designed to do, so no sense if changing it.
• Images (or any file) can be associated to a JSON node through a "src" property. That would have tied a lot of data together allowing for easy integration of Gatsby-image instead of having to do it manually later.
• The current way of doing inline-styles makes everything a bit brittle, stlyed-components could have made things more robust and modular
• In the future, doing the pages as .mdx (markdown with JSX) would make editing easier for the non-technical, but still allow for dynamic data card creation
• This was probably a better example of how to dip one's toe into Gatsby without getting to messy, meaning without using GraphQL, and Markdown, and using more plain HTML and JS

@nohorse Not sure if we ever want to fork this project, because I see how it could have been designed a lot better, but it is still an artifact of an open website we worked on :)