Test that everything works when a schema is created or modified

[psrpinto]

Test cases:

• Add a field to an existing schema and make sure everything works
• Create a new schema under schemas/subjects/ and make sure everything works

[psrpinto]

Created this ticket because it's an action we need to do, and it also serves as the "finish line" for the work related to having schemas drive the system.

[ashfame]

I did a round of testing. Created #178 and I believe schema is driving all aspects of frontend and backend correctly now.

Here is how I tested it:

I created a test.json under schema/subjects directory with the following content:

{
	"title": "Page-two",
	"slug": "page-two",
	"fields": {
		"title": {
			"description": "The title of the page2",
			"type": "text"
		},
		"content": {
			"description": "The body of the page2",
			"type": "html"
		}
	}
}

Ran extension: npm run start:chrome

Subject import option shows up:

Proceeding:

Defining subject definition:

Preview: