Added link to the FAQ in the Linux instructions.

docs/en/shared/install.md

@@ -52,3 +52,5 @@ Installation on Linux
   $ cd Defold
   $ ./Defold
   ``` 
+
+  If you run into any problems starting the editor, opening a project or running a Defold game please refer to the [Linux section of the FAQ](../faq/faq.md).