Updating @JLayer Docstring

[TheCedarPrince]

PR Checklist

If you are contributing to Javis.jl, please make sure you are able to check off each item on this list:

• Did I update CHANGELOG.md with whatever changes/features I added with this PR?
• Did I make sure to only change the part of the file where I introduced a new change/feature?
• Did I cover all corner cases to be close to 100% test coverage (if applicable)?
• Did I properly add Javis dependencies to the Project.toml + set an upper bound of the dependency (if applicable)?
• Did I properly add test dependencies to the test directory (if applicable)?
• Did I check relevant tutorials that may be affected by changes in this PR?
• Did I clearly articulate why this PR was made the way it was and how it was made?

Link to relevant issue(s)
Closes #382

How did you address these issues with this PR? What methods did you use?

This fixes some issues with the JLayers docstring. I started by fixing the example that is within the docstring itself. @Sov-trotter - feel free to add the rest of your changes here to address issue #382

[codecov]

Codecov Report

Merging #383 (034cd79) into master (41f84e7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #383   +/-   ##
=======================================
  Coverage   95.98%   95.98%           
=======================================
  Files          27       27           
  Lines        1369     1369           
=======================================
  Hits         1314     1314           
  Misses         55       55           

Impacted Files	Coverage Δ
src/layers.jl	84.37% <ø> (ø)

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[Wikunia]

We might just wanna merge this as this fixes one part of the docstring and just keep #382 open though to fix the others

[Wikunia]

@TheCedarPrince can we merge this?

[TheCedarPrince]

Yes, I think there was more I wanted to do here, but I can open other issues to review docs later.
Merging now.