Add dependencies section for Maven project support

Readme.md

@@ -3,6 +3,16 @@
 An [extension for coc.nvim](https://github.com/neoclide/coc.nvim/wiki/Using-coc-extensions) to enable
 [Groovy language server](https://github.com/prominic/groovy-language-server) support.
 
+## Features
+
+- Maven and Gradle project support
+- Code Completion
+- Find References
+- Go to Definition
+- Highlights
+- Refactor Rename
+- Signature Hover
+
 ## Quick Start
 
 1. Download and install a recent Java Development Kit (latest Java 8 is the minimum requirement).
@@ -12,15 +22,15 @@ An [extension for coc.nvim](https://github.com/neoclide/coc.nvim/wiki/Using-coc-
 ```
 3. This extension is activated when you first open a Groovy file.
 
-## Features
+## Dependencies
 
-- Maven and Gradle project support
-- Code Completion
-- Find References
-- Go to Definition
-- Highlights
-- Refactor Rename
-- Signature Hover
+### Maven Projects
+
+Maven project support requires having the [Maven Wrapper][0] installed in your
+project or having [Maven][1] installed on your environment path.
+
+* [Maven Wrapper][0]
+* [Installing Maven][1]
 
 ## Available commands
 
@@ -51,3 +61,6 @@ The path to the Java Development Kit is searched in the following order:
 ## License
 
 EPL 2.0, See [LICENSE](LICENSE) for more information.
+
+[0]: https://maven.apache.org/wrapper/
+[1]: https://maven.apache.org/install.html