[WIP] Allow flipbook to be required as a Wally package

[vocksel]

The idea is all of our storybook and story-related functionality and types to be exposed off of a public API that creators could import via Wally.

One of the primary benefits would be to allow type-checking within storybook and story files. For example:

-- Foo.storybook.lua
local flipbook = require(Path.To.Packages.flipbook)

local storybook: flipbook.Storybook = {
    storyRoots = true -- analysis error
}

return storybook

-- Bar.story.lua
local flipbook = require(Path.To.Packages.flipbook)

local story: flipbook.Story = {
    -- TODO: show analysis error
}

return story

Proposed API

Types

export type Controls = {
	[string]: string | number | boolean,
}

export type StoryProps = {
	controls: Controls,
}

export type Storybook = {
	storyRoots: { Instance },
	name: string?,
	roact: Roact?,
	react: React?,
	reactRoblox: ReactRoblox?,
}

export type StoryMeta = {
	name: string,
	summary: string?,
	controls: Controls?,
	roact: Roact?,
	react: React?,
	reactRoblox: ReactRoblox?,
}

export type RoactStory = StoryMeta & {
	story: RoactElement | (props: StoryProps) -> RoactElement,
	roact: Roact,
}

export type ReactStory = StoryMeta & {
	story: ReactElement | (props: StoryProps) -> ReactElement,
	react: React,
	reactRoblox: ReactRoblox,
}

export type FunctionalStory = StoryMeta & {
	story: (target: GuiObject, props: StoryProps) -> (() -> ())?,
}

export type Story = FunctionalStory | RoactStory | ReactStory

Functions

isStoryModule(instance: Instance): boolean

isStorybookModule(instance Instance boolean

useStorybooks(): { Storybook }