fix: do not exclude d.ts files, and add install test

[AVaksman]

Fixes #544

• Tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

[codecov]

Codecov Report

Merging #545 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #545   +/-   ##
=======================================
  Coverage   97.79%   97.79%           
=======================================
  Files          10       10           
  Lines        1313     1313           
  Branches      347      347           
=======================================
  Hits         1284     1284           
  Partials       29       29

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