[2.7.0] Add Bengali, Azerbaijani, Arabic (Saudi Arabia) and German (Austria) to languages
[2.7.0] Add spm install instructions
Add link to NuGet in use-it section
[2.7.0] Document add/subtract(String, String) variant
[2.7.0] Deprecate instance min/max, document class min/max
[2.7.0] Document special formats (moment.ISO_8601)
[2.7.0] Document calendar(referenceTime)