Add HoD transform

[nicoleepp]

Part of #6

Supersedes #11

[codecov]

Codecov Report

Merging #16 (e79b2fc) into main (670f4b3) will decrease coverage by 0.94%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #16      +/-   ##
==========================================
- Coverage   93.58%   92.64%   -0.95%     
==========================================
  Files           6        7       +1     
  Lines          78       68      -10     
==========================================
- Hits           73       63      -10     
  Misses          5        5              

Impacted Files	Coverage Δ
src/Transforms.jl	100.00% <ø> (ø)
src/temporal.jl	100.00% <100.00%> (ø)
src/transformers.jl	95.23% <0.00%> (-0.60%)	⬇️
src/power.jl	100.00% <0.00%> (ø)
src/periodic.jl	100.00% <0.00%> (ø)
src/linear_combination.jl	100.00% <0.00%> (ø)

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[bencottier]

Looks good to me - just spotted a couple typos in the tests.