Tweak to gradlew/gradlew.bat + better .gitignore

Made it automatically allocate itself 2 GB of RAM so it doesn’t
constantly crash if anyone decides to run it again or any 3rd party
ever decides they might wanna add a feature and send a pull request.
Also updated .gitignore to ignore IntellijIDEA project files in case
anyone used those because reasons?

Anywho, it’s my first commit to the new updated project! Excitement!