Document PoS concept page (#1125)

* Document PoS concept page

Signed-off-by: Roland Tyler <roland.tyler@consensys.net>

* Nav fix

Signed-off-by: Roland Tyler <roland.tyler@consensys.net>

Signed-off-by: Roland Tyler <roland.tyler@consensys.net>

docs/public-networks/concepts/proof-of-stake.md

@@ -0,0 +1,52 @@
+---
+description: Ethereum proof of stake
+---
+
+# Proof of stake
+
+[The Merge](the-merge.md) transitions Ethereum Mainnet to
+[proof of stake (PoS)](https://ethereum.org/en/developers/docs/consensus-mechanisms/pos/) consensus.
+
+PoS is preferred over proof of work and proof of authority as a consensus mechanism
+because it is more secure, requires less energy, and lowers the barrier to entry.
+
+The PoS mechanism randomly chooses validators to propose or validate blocks on the
+[Beacon Chain](https://ethereum.org/en/upgrades/beacon-chain/) in defined time frames.
+
+Proposers are responsible for proposing new consensus blocks, and non-proposing validators are responsible for
+validating (attesting to) proposed blocks.
+Validators are rewarded for proposing and attesting to consensus blocks eventually included in the Beacon Chain, and
+penalized for malicious behavior.
+Validators also receive [transaction fees](https://docs.teku.consensys.net/en/latest/HowTo/Prepare-for-The-Merge/#configure-the-fee-recipient) for included
+blocks.
+
+Each consensus block contains an execution payload, which contains a list of transactions and other data required to
+execute and validate the payload.
+
+When a node validates a consensus block, its [consensus client](the-merge.md#consensus-clients) processes
+the block and sends the execution payload to the [execution client](the-merge.md#execution-clients), which:
+
+1. Assembles a block on the execution layer.
+1. Verifies pre-conditions.
+1. Executes transactions.
+1. Verifies post-conditions.
+1. Sends the validity result back to the consensus client.
+
+If the block is valid, the execution client includes it in the execution chain and stores the new state in execution
+state storage.
+
+If a consensus block receives attestations backed by enough staked ETH, the block is included in the Beacon Chain.
+
+In Ethereum's PoS, you must run a [full node](the-merge.md#execution-and-consensus-clients) and
+[stake 32 ETH](https://ethereum.org/en/staking/) to become a validator.
+
+!!! important
+
+    Withdrawing staked ETH isn't yet supported and will be included in a separate upgrade following The Merge.
+
+!!! note
+
+    You must run a beacon node and an execution client to operate a full node on Mainnet post-Merge.
+    To become a validator, you must also run a validator client (either
+    [in the same process as the beacon node](https://docs.teku.consensys.net/en/stable/HowTo/Get-Started/Run-Teku/#start-the-clients-in-a-single-process) or
+    [separately](https://docs.teku.consensys.net/en/stable/HowTo/Get-Started/Run-Teku/#run-the-clients-separately)).

docs/public-networks/concepts/the-merge.md

@@ -8,7 +8,7 @@ description: What is the Merge?
 Ethereum Mainnet, turning Mainnet into a combination of an
 [execution layer and consensus layer](#execution-and-consensus-clients).
 The Merge transitions Mainnet from proof of work to
-[proof of stake consensus](https://docs.teku.consensys.net/en/stable/Concepts/Proof-of-Stake/).
+[proof of stake consensus](proof-of-stake.md).
 
 Update and configure Besu to be [ready for The Merge](../how-to/prepare-for-the-merge.md).
 You can also test Besu with a consensus client such as [Teku] on the [Kiln Merge testnet](../tutorials/merge-testnet.md).
@@ -34,7 +34,7 @@ peer-to-peer network.
 
 Consensus clients, such as [Teku], contain beacon node and validator client implementations.
 The beacon node is the primary link to the [Beacon Chain] (consensus layer).
-The validator client performs [validator duties](https://docs.teku.consensys.net/en/latest/Concepts/Proof-of-Stake/) on
+The validator client performs [validator duties](proof-of-stake.md) on
 the consensus layer.
 Consensus clients serve [REST API](https://docs.teku.consensys.net/en/stable/Reference/Rest_API/Rest/) requests and
 communicate with each other in a peer-to-peer network.
@@ -60,7 +60,7 @@ To become a validator, you must also run a validator client (either
 or [separately](https://docs.teku.consensys.net/en/stable/HowTo/Get-Started/Run-Teku/#run-the-clients-separately).
 
 After The Merge, validators earn rewards for performing
-[validator duties](https://docs.teku.consensys.net/en/stable/Concepts/Proof-of-Stake/), and
+[validator duties](proof-of-stake.md), and
 [fee recipients](https://docs.teku.consensys.net/en/latest/HowTo/Prepare-for-The-Merge/#configure-the-fee-recipient)
 will also earn rewards for the inclusion of execution layer transactions.
 

mkdocs.navigation.yml

@@ -58,6 +58,7 @@ nav:
               - Trace transactions: public-networks/how-to/troubleshoot/trace-transactions.md
       - Concepts:
           - The Merge: public-networks/concepts/the-merge.md
+          - Proof of stake: public-networks/concepts/proof-of-stake.md
           - Data storage formats: public-networks/concepts/data-storage-formats.md
           - Transactions:
               - Transaction types: public-networks/concepts/transactions/types.md

mkdocs.redirects.yml

@@ -44,7 +44,7 @@ plugins:
       HowTo/Deploy/Lite-Network-Monitor.md: https://github.com/Alethio/ethstats-network-dashboard
       HowTo/Configure/Consensus-Protocols/QuorumIBFT.md: private-networks/how-to/configure/consensus/qbft.md
       HowTo/Configure/Configure-Data-Storage.md: public-networks/concepts/data-storage-formats.md
-      Concepts/Consensus-Protocols/Proof-of-Stake.md: public-networks/concepts/the-merge.md
+      Concepts/Consensus-Protocols/Proof-of-Stake.md: public-networks/concepts/proof-of-stake.md
       Tutorials/Examples/Private-Network-Example.md: private-networks/tutorials/quickstart.md
       Tutorials/Examples/Privacy-Example.md: private-networks/tutorials/privacy/quickstart.md
       Tutorials/Examples/Nat-Manager-Kubernetes.md: private-networks/tutorials/kubernetes/nat-manager.md