Added Identifiers, Lexical Structure, and Literals. I pushed kasi minamadali na ako nila lemuel
Added DataTypes, Objects, Variables, GarbageCollection, and Operators in Chapter2
Merge branch 'Chapter2' of https://github.com/RomeoVargas/PHP_TryOuts into Chapter2
Added FlowControl_Statements in Chapter2
Merge branch 'Chapter2' of https://github.com/RomeoVargas/PHP_TryOuts into dev_1.0