Added mono

.gitpod

@@ -1,3 +1,5 @@
+image:
+  file: Dockerfile
 ports:
   - port: 3000
     protocol: "http"

Dockerfile

@@ -0,0 +1,10 @@
+FROM gitpod/workspace-full:latest
+
+USER root
+# comment
+RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF \
+    && echo "deb https://download.mono-project.com/repo/ubuntu stable-bionic main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list \
+    && apt update \
+    && apt-get update \
+    && apt-get install -y mono-devel \
+    && apt-get clean && rm -rf /var/cache/apt/* && rm -rf /var/lib/apt/lists/* && rm -rf /tmp/*

README.md

@@ -1,7 +1,7 @@
 # C# Extension For Theia
 [![Gitpod - Code Now](https://img.shields.io/badge/Gitpod-Code%20Now-blue.svg?longCache=true)](https://gitpod.io#https://github.com/theia-ide/theia-csharp-extension)
 
-Adds C# language support to the Theia IDE.
+Adds C# language support to the Theia IDE. Powered by omnisharp.
 
 ## Getting started