ruby: 0000-fundamentals.rb: add math objects
ruby: 0000-fundamentals.rb: add math objects

This patch is created to add math objects note. Math object includes
advanced math like Math::PI, Math::E, Math::cos and Math.sqrt.

Signed-off-by: (Holloway) Chew, Kean Ho <bbd8faa40b0f348214bf4124b281a301299ba6dd@gmail.com>

hollowaykeanho/learning,hollowaykeanho/learning,josiahsoh/learning,josiahsoh/learning,hollowaykeanho/learning,josiahsoh/learning,josiahsoh/learning,hollowaykeanho/learning,hollowaykeanho/learning,josiahsoh/learning