datasource/ethereum: Add link to finality blog post
@@ -266,6 +266,8 @@ where
// are chained on after that block.
// Eventually, the probability is so low, that a block is effectively permanent.
// The "effectively permanent" part is what makes blockchains useful.
+ // See here for more discussion:
+ // https://blog.ethereum.org/2016/05/09/on-settlement-finality/
//
// Accordingly, if the subgraph ptr is really far behind the head ptr, then we can
// trust that the Ethereum node knows what the real, permanent block is for that block
