How to include DSL Foundry dependency in IntelliJ plugin zip file?

MPS Version 2018.1

IntelliJ Version 2018.1

I am attempting to build an IntelliJ plugin using the instructions here:

https://confluence.jetbrains.com/display/MPSD32/Building+IntelliJ+IDEA+language+plugins

I didn't have any problems until I tried to generate my model inside IntelliJ once the plugin was installed. I receive this error:

"Language com.dslfoundry.plaintextgen is not in repository".

I am using plaintextgen to create a markdown file from a model.

I have inspected the .zip file created by the MPS build process and indeed it only contains binaries for my language, not for plaintextgen.

I have tried to google for how to bundle dependencies inside this zip file, but have not had any luck. 

Is there anything I can add to the below to make sure plaintextgen binaries are included in the zip for install into IntelliJ?

build VsuiteDsl generates build.xml

base directory: ../../ 

use plugins:
java
mps

macros:
folder idea_home = ./../../.local/share/JetBrains/Toolbox/apps/IDEA-U/ch-0/181.4668.68
folder plugins_home = ./../../.IntelliJIdea2018.1/config/plugins

dependencies:
IDEA (artifacts location $idea_home)
mpsPlugin (artifacts location $plugins_home)
com.dslfoundry.plaintextgen (artifacts location ./)

project structure:
idea plugin VsuiteDsl from generated by default 'plugin.xml' descriptor file
name VsuiteDsl
short (folder) name VsuiteDsl
description <no description>
version 1.0.2
<< no vendor >>
content:
VsuiteDsl
dependencies:
jetbrains.mps.core
com.dslfoundry.plaintextgen
<< ... >>

mps group VsuiteDsl
language ChangeLogDsl
load from ./languages/ChangeLogDsl/ChangeLogDsl.mpl


default layout:
zip VsuiteDsl.zip
plugin VsuiteDsl
<empty>

<<additional aspects>>
/home/gshaw/MPSProjects/VsuiteDsl