Basic file layout of references (ledger formats, transaction formats)

content/references/rippled-api/ledger-data-formats/ledger-data-formats.md

@@ -0,0 +1,11 @@
+# Ledger Data Formats
+
+{{currentpage.blurb}}
+
+* **[Ledger Header](x)**
+<!--{# TODO: provide overview text of what this content is all about #}-->
+
+* **[Ledger Object Types](x)**
+<!--{# TODO: provide overview text of what this content is all about #}-->
+
+<!--{# TODO: This page may need to catch overflow of any doc from https://developers.ripple.com/reference-ledger-format.html#xrp-ledger-data-format that hasn't been moved out to Ledger Header and Ledger Object Type docsIf yes - need to adjust presentation of links to child pages above because they may look like anchor links to topics on the page and cause confusion. Ideally, we'd provide another page in this hierarchy that reflects the content in the overflow. #}-->