Add build script for netlify

[zakpatterson]

What kind of change does this PR introduce? (delete not applicable)

• Build-related changes

Allow PRs to change how netlify runs

[codecov]

Codecov Report

Merging #750 (3423387) into master (c002332) will decrease coverage by 0.89%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #750      +/-   ##
==========================================
- Coverage   71.02%   70.12%   -0.90%     
==========================================
  Files         114      114              
  Lines        3786     3786              
  Branches      587      587              
==========================================
- Hits         2689     2655      -34     
- Misses       1083     1117      +34     
  Partials       14       14              

Impacted Files	Coverage Δ
src/util.ts	75.86% <0.00%> (-20.69%)	⬇️
src/irsForms/ScheduleEIC.ts	63.12% <0.00%> (-16.21%)	⬇️
src/irsForms/worksheets/ChildTaxCreditWorksheet.ts	97.67% <0.00%> (-2.33%)	⬇️
src/irsForms/Schedule8812.ts	98.52% <0.00%> (+2.94%)	⬆️

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