Update WP5.0_Library.sketch

[oszkarnagy]

The big cleanup in Sketch file:

• Renamed /Block/Insert_new to /Block/Manage/Add block
• Renamed /Block/Change_inline to /Block/Manage/More options
• Cleaned up /Blocks page and annotations
• Renamed 1_New_Post_Shell to /Page/New post
• Renamed “Setting Sidebars” to “Sidebars”
• Cleaned up Sidebars page and annotations
• Renamed “Core/Publish-Title” to /Page/Elements/Editor top bar
• Renamed /dashicon/cursor/ to /Icon/Annotate/
• Renamed symbols for consistent variant naming with — and removed spaces
• Editor top sidebar - added symbols for icons and buttons
• Added /Icon/Check
• Added symbols to Editor page shell
• Cleaned up Icons page and annotations
• Renamed “Page shells” to “Pages”
• Renamed “Navigation wrapper” to “Page elements” and organised and namespaced all page elements consistently in there
• Merged Sidebar symbols into Page elements and deleted “Sidebar” page
• Added text styles to /Page/Element/Nav/Subnav so that they can be overridden in symbols for easier page level usage
• Cleaned up /Input
• Namespaced Notifications/*

And other minor OCD arrangements for consistency