feature: Arabic language support

[lamamyf]

Hey,

Fixing #42

• Translated ar.json & added it to /misc folder.
• Added ARABIC ENUM and corresponding case in EfficientNetLanguageProvided.ts.
• Added a minimal test based on the example.
• Updated Multilingual status in README.md.

[ntedgi]

Thanks a lot Please review and pass CI TESTS

‏https://app.codacy.com/gh/ntedgi/node-efficientnet/pullRequest?prid=8705666

[lamamyf]

Done

[ntedgi]

closes #42