v2.6.0

Added

• Add smith subplots and the scattersmith trace type for displaying Smith charts [#5956, #5992],
  with thanks to Kitware and @waxlamp for kicking off this effort.

Changed

• Improve drawing the contour lines in non-linear space e.g. on log axes [#5985], with thanks to @andrew-matteson for the contribution!
• Bump eslint to v8 release candidate including fixes for no-new-func test [#5969]

Fixed

• Fix npm install problem for npm v6 users (regression introduced in 2.5.0) [#6004]
• Fix unhover event data for gl3d subplots [#5954],
  with thanks to @dwoznicki for the contribution!
• Fix scatter3d opacity restyle bug [#5958],
  with thanks to @dwoznicki for the contribution!
• Skip "hoverinfo": "none" trace display for hover modes [#5854],
  with thanks to @Domino987 for the contribution!
• Display prefix and suffix of invisible polar axes in hover [#5964]
• Reduce calls to getBoundingClientRect in convertToTspans [#5976]
• Avoid wrapping legend items if already on the first column [#5996]
• Fix horizontal alignment of colorbar in editable mode when xanchor is set to "center" [#6002]
• Fix to improve rendering of graphs with Mathjax on Firefox v82 and higher [#5993]