Add docker instructions

README.md

@@ -9,11 +9,11 @@ A command-line tool for managing common tasks in Ethereum 2.
 
 ## Table of Contents
 
-- [Install](#install)
-- [Usage](#usage)
-- [Maintainers](#maintainers)
-- [Contribute](#contribute)
-- [License](#license)
+- [Commands](#commands)
+- [HOWTO](#howto)
+  - [Maintainers](#maintainers)
+  - [Contribute](#contribute)
+  - [License](#license)
 
 ## Install
 
@@ -27,6 +27,20 @@ Note that `ethdo` requires at least version 1.13 of go to operate.  The version
 
 If this does not work please see the [troubleshooting](https://github.com/wealdtech/ethdo/blob/master/docs/troubleshooting.md) page.
 
+## Docker
+
+It is possible to build the tool using docker:
+
+```sh
+docker build -t ethdo .
+```
+
+You can run the tool using docker after that. Example:
+
+```sh
+docker run -it ethdo --help
+```
+
 ## Usage
 
 ethdo contains a large number of features that are useful for day-to-day interactions with the Ethereum 2 blockchain.