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

consensus/ssz/src/decode/impls.rs

@@ -1,6 +1,6 @@
 use super::*;
 use core::num::NonZeroUsize;
-use ethereum_types::{H256, U128, U256};
+use ethereum_types::{H160, H256, U128, U256};
 use smallvec::SmallVec;
 use std::sync::Arc;
 
@@ -256,6 +256,27 @@ impl<T: Decode> Decode for Arc<T> {
     }
 }
 
+impl Decode for H160 {
+    fn is_ssz_fixed_len() -> bool {
+        true
+    }
+
+    fn ssz_fixed_len() -> usize {
+        20
+    }
+
+    fn from_ssz_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
+        let len = bytes.len();
+        let expected = <Self as Decode>::ssz_fixed_len();
+
+        if len != expected {
+            Err(DecodeError::InvalidByteLength { len, expected })
+        } else {
+            Ok(Self::from_slice(bytes))
+        }
+    }
+}
+
 impl Decode for H256 {
     fn is_ssz_fixed_len() -> bool {
         true