Fixed BC break
Added missing license headers
Merge branch 'bc-break'
[1.2.1] Updated CHANGELOG
[Run] Moved EditorSpec methods by category
[Run] Added Editor::run
[Run] Added Command extension documentation
Removed references to LineNumberSearchStrategy
[Run] Created LineJumpAboveCommand
[Run] Created LineJumpBelowCommand
[Run] Added doc for LineJumpAboveCommand and LineJumpBelowCommand
[Run] Added LineAppendCommand
[Run] Added LinePrependCommand
[Run] Added doc for LineAppendCommand and LinePrependCommand
[Run] Fixed typo
[Run] Added @api to Editor#run()
[Run] Added LineJumpPercentCommand
[Run] Added doc for LineJumpPercentCommand
[Run] Improved Commands reference
[Run] Added comments for the JumpPercent reference