v1.2.0

Changelog

• feat: First-class Kotlin language support
• feat: Java 8 language features support (lambda expressions, method references, etc.)
• feat: rush upgrade command
• feat: Markdown support in the extension description
• feat: Auto-completion for the metadata file (rush.yml) in select IDEs
• fix: Having no block annotation in the source file would crash Rush
• fix: Multiline extension description won't show as expected in the builder
• fix: Warnings would get mixed up with errors
• fix: Processing extension would sometimes fail on macOS and Linux
• fix: Sometimes errors would have the phrase src in front of them
• fix: Optimized extensions would sometimes clash with each other
• fix: Migrated extensions without an icon image won't build
• misc: Slightly changed terminal-UI
• misc: Improved validation for the metadata file (rush.yml)
• misc: Deprecated rush-init in the favor of install scripts
• misc: Deprecated release and license_url fields