KdV example in the docs

[ranocha]

Animation for the docs:

[codecov]

Codecov Report

Merging #144 (8c42aca) into main (af4ce8d) will decrease coverage by 0.70%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #144      +/-   ##
==========================================
- Coverage   89.91%   89.21%   -0.71%     
==========================================
  Files          31       31              
  Lines        4908     5061     +153     
==========================================
+ Hits         4413     4515     +102     
- Misses        495      546      +51     

Flag	Coverage Δ
unittests	89.21% <ø> (-0.71%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/var_coef_operators.jl	88.50% <0.00%> (-6.56%)	⬇️
src/fourier_operators_2d.jl	86.74% <0.00%> (-4.05%)	⬇️
src/fourier_operators.jl	80.90% <0.00%> (-2.00%)	⬇️
src/dissipation_operators.jl	91.91% <0.00%> (-1.77%)	⬇️
src/legendre_operators.jl	79.50% <0.00%> (-1.33%)	⬇️
src/general_operators.jl	82.14% <0.00%> (-0.83%)	⬇️
src/SBP_operators.jl	77.69% <0.00%> (-0.78%)	⬇️
src/coupling.jl	90.46% <0.00%> (-0.67%)	⬇️
src/filter.jl	58.82% <0.00%> (-0.37%)	⬇️
src/SBP_coefficients/MattssonSvärdNordström2004.jl	98.73% <0.00%> (-0.27%)	⬇️
... and 2 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more