MAINT: improve examples

[GuillemBarroso]

Improvements in the example section.

• Several modifications in the examples descriptions to fix typos, class and function paths and to rewrite some sentences.
• Addition of absolute and relative error plots when two fields are compared.
• Addition of line plot when mapping field to a path.

@PProfizi, @MaxJPRey, feedback will be greatly appreciated.

[codecov]

Codecov Report

Merging #609 (7fac551) into master (be8d22d) will increase coverage by 0.11%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #609      +/-   ##
==========================================
+ Coverage   87.90%   88.02%   +0.11%     
==========================================
  Files          68       69       +1     
  Lines        7566     7623      +57     
==========================================
+ Hits         6651     6710      +59     
+ Misses        915      913       -2     

[MaxJPRey]

Thanks @GuillemBarroso for taking time to review and work with all those examples.

[PProfizi]

@GuillemBarroso For the last Codacy warning remaining, I am basing my fix on this page: https://security.openstack.org/guidelines/dg_use-subprocess-securely.html

[GuillemBarroso]

@GuillemBarroso For the last Codacy warning remaining, I am basing my fix on this page: https://security.openstack.org/guidelines/dg_use-subprocess-securely.html

Great, thanks @PProfizi. I am rerunning the only check that failed and as soon as it passes, we can merge.

[PProfizi]

@GuillemBarroso What is that skipping for?

[GuillemBarroso]

D400 indicates that the first line should end with a period, see doc.

@PProfizi, as we discussed, I will add the rule of ignoring D400 for the examples in the next PR, when I update the layout of the repo and I add the pre-commit.