[doc] Update the build instructions to make things easier for users

Author: adamretter

BUILD.md

@@ -4,22 +4,33 @@ Elemental itself is written in Java 8. The build system is [Apache Maven](http:/
 
 To build Elemental:
 
-- Checkout the Git Repository
-- Execute a Maven to compile Elemental
+1. Checkout the Git Repository
 
-```bash
-$ git clone https://github.com/evolvedbinary/elemental.git
-$ cd elemental
-$ git checkout gold
-$ mvn -DskipTests package
-```
+    ```bash
+    $ git clone https://github.com/evolvedbinary/elemental.git
+    $ git checkout gold
+    $ cd elemental
+    ```
+
+2. Execute Maven to compile Elemental
+
+    We provide a build script to try and make common build tasks easier for users.
+
+    For macOS/Linux/Unix platforms:
+    ```bash
+    $ ./build.sh quick
+    ```
+
+    or, for Windows platforms:
+    ```cmd
+    > build.bat quick
+    ```
 
 From here, you now have a compiled version of Elemental in the `exist-distribution/target` folder that you may use just as you would an installed version of Elemental. An installer is also build and present in `exist-installer/target` for easy installation elsewhere.
 
-Useful build switches:
-- `-Ddocker=true` : builds the docker image
-- `-DskipTests` : skips running tests
-- `-Ddependency-check.skip=true` : skips validating dependencies
+The `quick` build target will build distribution directory that can be found at: `exist-distribution/target/elemental-x.y.x-dir`.
+If you wish to see what other build targets are available, you can run `./build.sh --help` (or `build.bat --help` on Windows platforms).
+
 
 Further build options can be found at: [eXist-db Build Documentation](http://www.exist-db.org/exist/apps/doc/exist-building.xml "How to build eXist-db").