Render only specific frames for faster rendering

[Wikunia]

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?

How did you address these issues with this PR? What methods did you use?
Render only part of the frames can speed up the rendering process. It's not that much faster unfortunately as still every frame gets computed but still.

[codecov]

Codecov Report

Merging #342 (6320da0) into master (dcb7b0f) will decrease coverage by 0.04%.
The diff coverage is 94.11%.

@@            Coverage Diff             @@
##           master     #342      +/-   ##
==========================================
- Coverage   95.56%   95.51%   -0.05%     
==========================================
  Files          23       23              
  Lines        1195     1204       +9     
==========================================
+ Hits         1142     1150       +8     
- Misses         53       54       +1     

Impacted Files	Coverage Δ
src/Javis.jl	93.57% <94.11%> (-0.33%)	⬇️

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