Add some minor docs to indicate the existance of eth_data_exporter (#1637)

fluffy/README.md

@@ -119,6 +119,19 @@ Follow the steps outlined [here](../README.md#windows) to build fluffy on Window
 
 ## Development tools and documentation
 
+The fluffy directory also holds several tools to help development of the Portal
+networks.
+
+Command to build the tools:
+
+```bash
+make fluffy-tools -j6
+```
+
+Additional documention on the tools or on what you can use them for:
+
+- [eth_data_exporter](./docs/eth_data_exporter.md): tool to extract content from
+EL or CL and prepare it as Portal content and content keys.
 - [Content seeding](./docs/content_seeding.md): Documentation on how to retrieve & generate history data and how to seed it into the network
 - [Manual protocol interop testing](./docs/protocol_interop.md): commands on how to manually test the discv5 and Portal protocol request and responses
 - [Local testnet script](./docs/local_testnet.md): Documentation on the local testnet script and how to use it

fluffy/docs/eth_data_exporter.md

@@ -0,0 +1,20 @@
+# eth_data_exporter
+
+The `eth_data_exporter` is a tool to extract content from Ethereum EL or CL and
+prepare it as Portal content and content keys.
+
+The `eth_data_exporter` can export data for different Portal networks.
+Currently the `history` and the `beacon` networks are supported.
+
+Example commands:
+
+```bash
+# See the different commands and options
+./build/eth_data_exporter --help
+```
+
+```bash
+# Request of Beacon Chain Light Client Updates and export into the Portal
+# network supported format
+./build/eth_data_exporter beacon exportLCUpdates --rest-url:http://testing.mainnet.beacon-api.nimbus.team --start-period:816 --count:4
+```