Filter out storybooks in CoreGui

[vocksel]

Problem

When opening flipbook several warnings appear in the output from it attempting to load Roblox-created storybooks in CoreGui

  12:37:42.545  Failed to load storybook CoreGui.RobloxGui.Modules.VoiceChatPrompt.VoiceChatPrompt.storybook. Error: table expected, got nil  -  Edit - useStorybooks:40
  12:37:42.545  Failed to load storybook CoreGui.RobloxGui.Modules.Settings.Settings.storybook. Error: table expected, got nil  -  Edit - useStorybooks:40
  12:37:42.545  Failed to load storybook CoreGui.RobloxGui.Modules.InGameChat.BubbleChat.BubbleChat.storybook. Error: table expected, got nil  -  Edit - useStorybooks:40
  12:37:42.545  Failed to load storybook CoreGui.RobloxGui.Modules.TopBar.TopBar.storybook. Error: table expected, got nil  -  Edit - useStorybooks:40
  12:37:42.545  Failed to load storybook CoreGui.RobloxGui.Modules.ContactList.ContactList.storybook. Error: table expected, got nil  -  Edit - useStorybooks:40

Solution

To fix this, I've updated isStorybookModule to return false for any storybook in CoreGui

Closes #218

Checklist

• Ran ./bin/test.sh locally before merging

[passhley]

Overall looks fine to me, just a few changes