Release v0.0.3

Feature

• Text
  Add H4, H5, H6 tags
• PDFGridLayout
  Support Row-Span and Column-Span
• PDFBuilder
  Default quality is 60, and Default Dpi is M5, as 360
  Add a value that is a multiple of 2 to dpi class
• BinaryPDF
  Can change image compress quality.

Full Changelog: v0.0.2...v0.0.3