Add Blocknative Blob Archive to Dencun Historical Access

Added the Blocknative Blob Archive to the Dencun historical access page for researchers and public good projects to find. The Blocknative Blob Archive stores all blobs that land in the mempool (confirmed on-chain or not) for anyone to access. This data is available via API.

public/content/roadmap/dencun/index.md

@@ -48,6 +48,7 @@ While regular Ethereum nodes will always hold the _current state_ of the network
 _Historical_ blob data may be desired for a variety of reasons and can be stored and accessed using several decentralized protocols:
 
 - **Third-party indexing protocols**, such as The Graph, store this data through a decentralized network of node operators incentivized by crypto-economic mechanisms.
+- **[Blocknative Blob Archive](https://docs.blocknative.com/blocknative-data-archive/blob-archive)** stores all blobs that enter the mempool (confirmed on-chain or not) on the Ethereum network. Blob history accessable via API.
 - **BitTorrent** is a decentralized protocol where volunteers can hold and distribute this data to others.
 - **[Ethereum portal network](/developers/docs/networking-layer/portal-network/)** aims to provide access to all Ethereum data through a decentralized network of node operators by distributing data among participants akin to BitTorrent.
 - **Individual users** are always free to store their own copies of any data they wish for historical reference.