Add Holesky section to the guide

CHANGELOG.md

@@ -1,4 +1,4 @@
-2023-09-08 v23.9.0
+2023-09-12 v23.9.0
 ==================
 
 Nimbus `v23.9.0` is a `low-urgency` upgrade providing full support for the upcoming [Holešky testnet](https://github.com/eth-clients/holesky) and simplifying the required configuration for using [remote signers](https://nimbus.guide/web3signer.html).
@@ -16,6 +16,7 @@ We've been hard at work researching and developing a GossipSub protocol upgrade,
   https://github.com/status-im/nimbus-eth2/pull/5389
 
 * Nimbus now supports the upcoming Holešky testnet:
+  https://nimbus.guide/holesky.html
   https://github.com/status-im/nimbus-eth2/pull/5337
 
 * Faster validator registry processing reduces the time spent by Nimbus in state transitions and replays:

docs/the_nimbus_book/mkdocs.yml

@@ -82,6 +82,7 @@ nav:
       - 'profits.md'
       - 'health.md'
       - 'prater.md'
+      - 'holesky.md'
 
   - Security:
     - 'preparation.md'

docs/the_nimbus_book/src/holesky.md

@@ -0,0 +1,82 @@
+# Holešky testnet
+
+`holesky` will be launched on 15h of September to succeed Prater as the main long-running Ethereum testnet.
+
+It provides an opportunity to verify your setup works as expected through the proof-of-stake transition and in a post-merge context as well as to safely practice node operations such as adding and removing validators, migrating between clients, and performing upgrades and backups.
+If you come across any issues, please [report them here](https://github.com/status-im/nimbus-eth2/issues).
+
+## General Preparation
+
+1. Generate the JWT secret with `openssl rand -hex 32 | tr -d "\n" > "/opt/jwtsecret"`. This file needs to be passed to both the execution client and the consensus client.
+
+2. Choose an Ethereum address to receive transaction fees.
+   This ETH will be immediately available, not part of the staking contract.
+
+3. Download the [latest release](./binaries.md) and install it by unpacking the archive.
+
+4. Choose one of Nethermind, Besu, Erigon, or Geth as an execution client.
+   Download, install, and [run it](https://notes.ethereum.org/@launchpad/goerli#Run-an-Execution-Layer-Client).
+
+For example, Nethermind on Goerli can run via:
+```sh
+cd nethermind/src/Nethermind/Nethermind.Runner
+dotnet run -c Release -- --config holesky \
+--JsonRpc.Host=0.0.0.0 \
+--JsonRpc.JwtSecretFile=/opt/jwtsecret
+```
+
+Erigon can be run using:
+```sh
+./build/bin/erigon --chain=holesky \
+--datadir goerli-testnet \
+--authrpc.jwtsecret=/opt/jwtsecret \
+--http --http.api=engine,net,eth
+```
+
+and Besu can be run with the command:
+```sh
+build/install/besu/bin/besu     \
+  --network=holesky             \
+  --rpc-http-enabled=true       \
+  --rpc-http-host="0.0.0.0"     \
+  --rpc-http-cors-origins="*"   \
+  --sync-mode="X_SNAP"          \
+  --data-storage-format="BONSAI"\
+  --Xmerge-support=true         \
+  --rpc-ws-host="0.0.0.0"       \
+  --host-allowlist="*"          \
+  --engine-rpc-enabled=true     \
+  --engine-host-allowlist="*"   \
+  --engine-jwt-enabled=true     \
+  --engine-jwt-secret=/opt/jwtsecret
+```
+
+## Sync the beacon node and execution client
+
+5. [Start syncing](./start-syncing.md) the node consisting of Nimbus and chosen execution client, for example by running:
+```sh
+nimbus-eth2/build/nimbus_beacon_node \
+    --network=holesky \
+    --web3-url=http://127.0.0.1:8551 \
+    --rest \
+    --metrics \
+    --jwt-secret="/opt/jwtsecret" \
+    --suggested-fee-recipient=<Enter-eth-address-here>
+```
+
+!!! tip
+    If you want the syncing process to complete much faster, you can [sync from a trusted node](./trusted-node-sync.md).
+
+One might consider here to [set up a systemd service](./beacon-node-systemd.md) to ensure this runs automatically, including after restarts.
+
+## Obtaining genesis file (optional)
+
+By default, Nimbus will automatically download the genesis state of Holešky from Github through the HTTPS protocol. If something prevents you from using this method, you may be able to work-around the issue by either instructing Nimbus to use a different URL by specifying the `--genesis-state-url` command-line parameter (for example, you can point it to the `/eth/v2/debug/beacon/states/genesis` endpoint of a trusted beacon node or a checkpoint provider) or by downloading the `genesis.ssz` file of the network through some other means and then supplying its path through the `--genesis-state` command-line parameter.
+
+## Begin validating
+
+6. Once this Holešky node is [completely synced](./keep-an-eye.md#keep-track-of-your-syncing-progress), use the [Holesky launchpad](https://holesky.launchpad.ethereum.org/en/) to obtain Holesky validators.
+It might require some time before these enter and are activated on the beacon chain.
+If one does this before the node which will attest and propose using those validators has synced, one might miss attestations and block proposals.
+
+7. Follow our validating guide from [step 2 (import the validator keys) onward](./run-a-validator.md#2-import-your-validator-keys).