Add instructions for enabling linea-sequencer plugin

docs/architecture/stack/index.mdx

@@ -1,6 +1,6 @@
 ---
 title: Linea software
-image: /img/socialCards/the-linea-stack.jpg
+image: /img/socialCards/linea-software.jpg
 ---
 
 import DocCardList from "@theme/DocCardList";

docs/developers/guides/run-a-node/index.mdx

@@ -9,14 +9,18 @@ import DocCardList from "@theme/DocCardList";
 
 There are no financial incentives for running a Linea node, but it does allow you to:
 
-- Call the Linea JSON RPC API methods and submit transactions to the mempool without relying on an RPC provider.
-- Have a local copy of the Linea blockchain. This view of the state is "trusted" until the transaction, or the
-    block that transaction is in, has been finalized on L1.
+- Call the Linea JSON RPC API methods and submit transactions to the mempool without relying on an 
+RPC provider. Note that using [Linea-specific API methods](/developers/reference/api) such as 
+`linea_estimateGas` requires Besu and [the `linea-sequencer` plugin](/developers/guides/run-a-node/linea-sequencer). 
+- Have a local copy of the Linea blockchain. This view of the state is "trusted" until the 
+transaction, or the block that transaction is in, has been finalized on L1. You don't need to 
+install additional plugins to follow chain activity.
 
 :::note
 
-Running a sequencer node is currently not possible and there is no option to vote on blocks as part of the consensus
-mechanism or [fork-choice](https://eth2book.info/capella/part3/forkchoice/#whats-a-fork-choice) like on Ethereum.
+Running a sequencer node is currently not possible and there is no option to vote on blocks as part 
+of the consensus mechanism or [fork-choice](https://eth2book.info/capella/part3/forkchoice/#whats-a-fork-choice) 
+like on Ethereum.
 
 :::
 

docs/developers/guides/run-a-node/linea-sequencer.mdx

@@ -0,0 +1,37 @@
+---
+title: Install the linea-sequencer plugin for Besu
+description: How to install and configure the linea-sequencer plugin for Besu
+image: /img/socialCards/install-the-linea-sequencer-plugin-for-besu.jpg
+---
+
+# Install `linea-sequencer`
+
+If you want to run a Linea node and use it to interact with the blockchain, rather than running a 
+'follower' node that simply keeps a local copy of the chain, then you will need to install the 
+`linea-sequencer` plugin to ensure full functionality. This plugin only works with Besu.
+
+Specifically, the Linea-specific API methods documented in our [reference section](/developers/reference/api)
+will not work unless you install and configure `linea-sequencer`.
+
+## Steps
+
+1. From the [`linea-sequencer` releases page](https://github.com/Consensys/linea-sequencer/releases),
+download the `.jar` file for the latest release. 
+
+2. In the local Besu runtime directory (where you will run Besu from), create a directory called 
+`plugins` and place the `.jar` file there.
+
+3. In the Besu configuration file (called `config-mainnet.toml` if you downloaded the [file from 
+our instructions](pathname:///files/besu/config-mainnet.toml)), add `LINEA` to the list of RPC 
+methods:
+
+    ```
+    rpc-http-api=["ADMIN","NET","ETH","WEB3","TXPOOL","LINEA"]
+    ```
+
+    Alternatively, you can add `LINEA` to this list in the command line by running:
+    ```
+    --rpc-http-api=ADMIN,NET,ETH,WEB3,TXPOOL,LINEA
+    ```
+
+When you run Besu, you will see the `linea-sequencer` plugin registered during startup.

docs/developers/guides/run-a-node/use-binary.mdx

@@ -56,6 +56,19 @@ Download the genesis file and Besu configuration file.
 
 </Tabs>
 
+:::warning[Important: enable linea-sequencer]
+
+You must install and enable the `linea-sequencer` Besu plugin if you are offering RPC services or 
+hosting nodes. Enabling the plugin is a requirement for using certain API methods, such as 
+[`linea_estimateGas`](/developers/reference/api/linea-estimategas).
+
+Please see our [instructions for installing the plugin](./linea-sequencer).
+
+If you are running a node to follow the chain activity, rather than submit transactions, you don't 
+need to install `linea-sequencer`.
+
+:::
+
 ### Step 3. Define disk space volume (optional) {#disk-space-besu}
 
 Define a volume size appropriate to your expected usage. As of March 20 2024, Besu nodes use:
@@ -72,9 +85,9 @@ Ensure you mount the Besu `data-path` to the custom volume when you start the no
 
 <VolumeCreation />
 
-### Step 4. Configure the Besu configuration file.
+### Step 4. Configure the Besu configuration file
 
-In your Besu configuration file (`config-mainnet.toml`, `config-goerli.toml`, or `config-sepolia.toml`), configure
+In your Besu configuration file (`config-mainnet.toml` or `config-sepolia.toml`), configure
 the following options:
 
 - Set `data-path` to the location you want to store your data. 

static/files/besu/config-mainnet.toml

@@ -3,7 +3,7 @@ data-path="/path/to/your/directory"
 
 
 # Sync mode and data layer implementation
-sync-mode="X_SNAP"
+sync-mode="SNAP"
 data-storage-format="BONSAI"
 Xsnapsync-synchronizer-flat-db-healing-enabled=true
 

static/files/besu/config-sepolia.toml

@@ -3,7 +3,7 @@ data-path="/path/to/your/directory"
 
 
 # Sync mode and data layer implementation
-sync-mode="X_SNAP"
+sync-mode="SNAP"
 data-storage-format="BONSAI"
 Xsnapsync-synchronizer-flat-db-healing-enabled=true