fornberg(2020) weights based on hermite-based finite difference

[yewalenikhil65]

same PR from SciML/DiffEqOperators.jl#501 and also #13

[ChrisRackauckas]

@xtalax review?

[yewalenikhil65]

hey @ChrisRackauckas
@xtalax reviewed partially on DiffEqOperator.jl here
I would like to work on extending this a bit in actually solving PDE, but currently caught up in some other work. I will get back to it late this month.
Till then this PR is good to be to merge as it won't break anything.

[xtalax]

Sorry about the delay, looks good to me

[yewalenikhil65]

Sorry about the delay, looks good to me

@xtalax I see new some changes from my last commits in fornberg file. i will do same, resolve some conflicts and re-submit new commits

[codecov]

Codecov Report

Merging #14 (d71125e) into master (de64d60) will not change coverage.
The diff coverage is 0.00%.

@@          Coverage Diff           @@
##           master     #14   +/-   ##
======================================
  Coverage    0.00%   0.00%           
======================================
  Files           8       8           
  Lines         413     427   +14     
======================================
- Misses        413     427   +14     

Impacted Files	Coverage Δ
src/discretization/fornberg.jl	0.00% <0.00%> (ø)

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[yewalenikhil65]

@xtalax Done from my side for this PR !