Initial merge changes

Added Execution Payload from Rayonism Fork

Updated new Containers to match Merge Spec

Updated BeaconBlockBody for Merge Spec

Completed updating BeaconState and BeaconBlockBody

Modified ExecutionPayload<T> to use Transaction<T>

Mostly Finished Changes for beacon-chain.md

Added some things for fork-choice.md

Update to match new fork-choice.md/fork.md changes

ran cargo fmt

Added Missing Pieces in eth2_libp2p for Merge

fix ef test

Various Changes to Conform Closer to Merge Spec

beacon_node/network/src/service.rs

@@ -302,6 +302,10 @@ impl<T: BeaconChainTypes> NetworkService<T> {
             ForkName::Altair => vec![fork_context
                 .to_context_bytes(ForkName::Altair)
                 .expect("Altair fork bytes should exist as it's initialized in ForkContext")],
+            // TODO: check this.. what even is this?
+            ForkName::Merge => vec![fork_context
+                .to_context_bytes(ForkName::Merge)
+                .expect("Merge fork bytes should exist as it's initialized in ForkContext")],
         }
     }
 }