Add an overall module docstring

[zelunw]

?ImageTransformations

Created using ModuleDocstrings.jl
with introduction and docstring for restrict copied from https://juliaimages.org/ImageTransformations.jl/dev/
and examples from
https://juliaimages.org/latest/pkgs/transformations/

[codecov]

Codecov Report

Merging #152 (d45c1e8) into master (85ec60f) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #152   +/-   ##
=======================================
  Coverage   90.27%   90.27%           
=======================================
  Files           8        8           
  Lines         216      216           
=======================================
  Hits          195      195           
  Misses         21       21           

Impacted Files	Coverage Δ
src/ImageTransformations.jl	83.33% <ø> (ø)

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[timholy]

Thanks for this! With a couple of tweaks I think this is mergeable.

[johnnychen94]

A typo and a question. Others look good to me. Thanks for the proposal.

[timholy]

Thanks, @zelunw!