Correct S3 in WENO scheme

[Iddingsite]

Hi,

Nice package!
This is a very minor modification, but going through the WENO code, I believe there is a cubed term in S3 (the smoothness parameter) that should not be there.
Not that it changes much at the moment, but I guess better to have that right than it coming back to bite you at some point! See for instance equation 3.34 in the book you cite (Osher and Fedkiw, 2003). But also others references.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 20.57%. Comparing base (a1982ff) to head (6e0605f).
Report is 7 commits behind head on main.

❗ There is a different number of reports uploaded between BASE (a1982ff) and HEAD (6e0605f). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (a1982ff)	HEAD (6e0605f)
	2	1

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #48       +/-   ##
===========================================
- Coverage   79.29%   20.57%   -58.73%     
===========================================
  Files          11       11               
  Lines         826      807       -19     
===========================================
- Hits          655      166      -489     
- Misses        171      641      +470     

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[maltezfaria]

Definitely a typo, thanks for catching it!