Support bluesky in Sharing url for books

[cderv]

Add bluesky in sidebar tools: https://quarto.org/docs/books/book-output.html#sidebar-tools

quarto-cli/src/project/types/book/book-config.ts

Lines 558 to 575 in b289945

	const kSharingUrls: Record<string, SidebarTool> = {
	linkedin: {
	icon: "linkedin",
	text: "LinkedIn",
	href: "https://www.linkedin.com/sharing/share-offsite/?url=|url|",
	},
	facebook: {
	icon: "facebook",
	text: "Facebook",
	url: "https://www.facebook.com/sharer/sharer.php?u=|url|",
	},
	twitter: {
	icon: "twitter",
	text: "Twitter",
	url: "https://twitter.com/intent/tweet?url=|url|",
	},
	};

quarto-cli/src/resources/schema/definitions.yml

Lines 1260 to 1265 in c870167

	sharing:
	maybeArrayOf:
	enum: [twitter, facebook, linkedin]
	description: |
	Sharing buttons to include on navbar or sidebar
	(one or more of `twitter`, `facebook`, `linkedin`)

Companion to #13566