Adds exclusion patterns for java development artifacts, i.e. .jdk, .gradle and .m2 directories.

Description

Dev environments such as IntelliJ pull additional JDK versions into .jdk directories.
.m2 and .gradle are artefact directories for Maven and Gradle respectively

Related Issue

Motivation and Context

Reduce amount of (temporary) artifacts that get backed up

How Has This Been Tested?

Change still provides valid JSON

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have read the CONTRIBUTING guide.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

I provide my contribution under the terms of the license of this repository and I affirm the Developer Certificate of Origin.