feat: pull code from cdk-library

[ahammond]

• baseline stuff
• pull the code over
• refactor - strip out refs to core.Stack
• chore: self mutation
• cleanups and tweaks

Fixes #

[codecov]

Codecov Report

Merging #4 (67d0f82) into main (9881879) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main        #4   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines          225       208   -17     
  Branches         5         5           
=========================================
- Hits           225       208   -17     

Impacted Files	Coverage Δ
src/index.ts	100.00% <100.00%> (ø)

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