added sparse array transposition with blocks for rows/cols switching and some docs updates for release prep
Merge branch 'master' of https://github.com/randym/axlsx
fix typo in specs
escape formula for conditional formatting
Merge remote-tracking branch 'randym/master'

* randym/master:
  escape formula for conditional formatting
  fix typo in specs
  added sparse array transposition with blocks for rows/cols switching and some docs updates for release prep