Add cloudfoundry page and api endpoint (proof of concept for local development)

[echappen]

Changes proposed in this pull request:

• Adds a demo page to the NextJS app that shows a list of your Cloud Foundry apps
• Adds instructions for how to access CF data in a local dev environment

Note that this is for demo purposes only and does not persist the CF auth token. Since this is for demo/proof-of-concept purposes, automated tests haven't been added.

Also note that NextJS will cache API GET requests by default. You can bust the cache by hard-refreshing the page (command + shift + r). More info on caching is in the NextJS docs.

Looking for feedback on:

• Would this be a good enough (for now) approach for local development?

Related to #48

Security considerations

• The environment file is gitignored so that none of these CF variables enter source control

[hursey013]

This is great! Especially appreciate the ongoing updates to the README ✨