Roadmap for v2.0

[Progi1984]

• Add declare strict_types for each file & Type each method

  • src/PhpWord/Collection
  • src/PhpWord/ComplexType
  • src/PhpWord/Element
  • src/PhpWord/Escaper
  • src/PhpWord/Exception
  • src/PhpWord/Metadata
  • src/PhpWord/Reader
  • src/PhpWord/Shared
  • src/PhpWord/SimpleType
  • src/PhpWord/Style
  • src/PhpWord/Writer
  • src/PhpWord/*

• PR Milestoned 2.0 : https://github.com/PHPOffice/PHPWord/pulls?q=is%3Aopen+is%3Apr+milestone%3A2.0.0

• Issues Milestoned 2.0 : https://github.com/PHPOffice/PHPWord/issues?q=is%3Aopen+is%3Aissue+milestone%3A2.0.0