Add Gradle download

[rat-moonshine]

Gradle binary can be downloaded from https://gradle.org/install/

[rat-moonshine]

Added Gradle download to MSDKI. macOS Gradle download link needs to be updated and tested.

[JoelProminic]

I see that you used the Gradle Enterprise license agreement for Gradle:

This is a separate service for build scans. If you check the SDK itself, you can see it uses Apache License 2.0: https://github.com/gradle/gradle/blob/master/LICENSE

Gradle uses 95M of space for me on macOS.

[JoelProminic]

We still need an entry for Gradle in "By Feature"

Title: "Gradle Integration"
Text: Enable builds and editor enhancements for Gradle projects

[rat-moonshine]

• Updated Gradle configuration information as necessary
• Auto-detection and auto-setup now happens inside Moonshine for Gradle
• GRADLE_HOME now applies in local environment setup process

[rat-moonshine]

I'm closing this as done. Please, reopen if any problem found.

[piotrzarzycki21]

Update release notes please with changes.

[JoelProminic]

We noticed today that the Gradle version was not populated in the About page. @rat-moonshine fixed this.

This workstation (macOS Yosemite) is the only case where I see the "Welcome to" text. It seems fine on the other builds, and this doesn't need to hold up the release.