This project serves as example/template to get started with the development of a language plugin for IntelliJ IDEA.
To run the plugin you need to open the project in Intellij IDEA, connect a Module SDK (Download from Jetbrains...) and generate the parser code on Brainfuck.bnf (Right Click - "Generate Parser Code")
Now you can run the plugin.
For further plugin development documentation see https://www.jetbrains.org/intellij/sdk/docs/basics/getting_started.html it also links the this more elaborate example https://github.com/JetBrains/intellij-sdk-docs/tree/master/code_samples/simple_language_plugin