Add Jest coverage report information and two more tests

README.md

@@ -33,6 +33,13 @@ npm run test
 npm run test:coverage
 ```
 
+For the coverage report:
+- % Stmts = percent of statements called
+- % Branch = percent of if/switch branches that have been checked
+- % Funcs = percent of functions called
+- % Lines = percent of lines covered
+- Uncovered Line #s = exactly what it sounds like
+
 #### Check for specific issues
 ```
 npm run lint | grep require-returns

__tests__/models/World.tests.ts

@@ -5,3 +5,14 @@ const world = new World();
 test('World has empty journal', () => {
 	expect(world.journal.count()).toBe(0);
 });
+
+test('World journal has an entry', () => {
+	world.journal.addEntry(0, 'Test');
+	expect(world.journal.count()).toBe(1);
+});
+
+test('World journal is cleared', () => {
+	world.journal.addEntry(1, 'Test 2');
+	world.journal.erase();
+	expect(world.journal.count()).toBe(0);
+});