refactor!: design overhaul (#1)

* refactor!: use atom functions

* docs: reformat api reference

* docs: showcase atom functions

* docs: remove unused import

* refactor: finalize updates

* chore: misc edits

src/__tests__/effect.spec.luau

@@ -0,0 +1,30 @@
+local atom = require(script.Parent.Parent.atom)
+local effect = require(script.Parent.Parent.effect)
+
+return function()
+	it("runs on state change", function()
+		local a = atom(0)
+		local b = atom(0)
+		local current
+		local unsubscribe = effect(function()
+			current = a() + b()
+		end)
+
+		expect(current).to.equal(0)
+
+		for index = 1, 3 do
+			a(index)
+			expect(current).to.equal(index)
+		end
+
+		for index = 1, 3 do
+			b(index)
+			expect(current).to.equal(a() + index)
+		end
+
+		unsubscribe()
+		a(4)
+
+		expect(current).to.equal(6)
+	end)
+end