Add copy button to code block in RTD

[mariodruiz]

• These changes will automatically add a copy button to the code blocks https://github.com/executablebooks/sphinx-copybutton

[codecov-commenter]

Codecov Report

Merging #1351 (ee31966) into image_v2.8 (0cdf6b9) will not change coverage. The diff coverage is n/a.

@@             Coverage Diff             @@
##           image_v2.8    #1351   +/-   ##
===========================================
  Coverage       46.49%   46.49%           
===========================================
  Files              28       28           
  Lines            4955     4955           
  Branches          971      971           
===========================================
  Hits             2304     2304           
  Misses           2594     2594           
  Partials           57       57           

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 0cdf6b9...ee31966. Read the comment docs.