epub: add docinfo

Author: willcl-ark

index_epub.adoc

@@ -1,8 +1,18 @@
 = Onboarding to Bitcoin Core
 include::settings.adoc[]
-:leveloffset: +1
+:doctype: book
+:lang: en
+:revdate: 2023-12-04
+:doctitle: Onboarding to Bitcoin Core
+:author: Will Clark
+:description: Onboarding documentation for Bitcoin Core developers.
+:keywords: bitcoin, core, crypto, p2p, consensus, node, wallet, docs
+:copyright: MIT Licensed
+:source: https://github.com/chaincodelabs/onboarding-to-bitcoin-core/
 :mermaid-format: png
 
+:leveloffset: +1
+
 include::all_chapters.adoc[]
 
 :leveloffset: -1