Update Readme.md

* 'develop' of https://github.com/ONLYOFFICE/sdkjs:
  Implemented creating a font map for footnotes.
  Fixed bug with add a new tables in the document. Keeping work on the new class CBlockLevelSdt.
  cursorGetPos
  == -> ===
  delete PointerEvent from externs
  Keeping work on a new class CBlockLevelSdt.
  update "google-closure-compiler", "grunt", "grunt-contrib-clean", "grunt-contrib-concat", "grunt-replace"
  getSelectionRangeValue
  Functions for work with page numbers of paragraph/table were moved in the base class.
  Write/read from binary a new classes.
  comment debug functions
  Removed unused code. Added type for base class and BlockLevelSdt class.
  .
  fix ansi symbol