Chore(ci): use build caches for CI jobs, update npm syntax

[mmaeng]

Closes #82

• Set pip and npm to be cached by github actions.
• update npm ci syntax to use --include=optional
• explicitly set line endings to be LF on git checkout

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Base: 98.54% // Head: 98.54% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (0346145) compared to base (c45322e).
Patch has no changes to coverable lines.

❗ Current head 0346145 differs from pull request most recent head 0f6fd4b. Consider uploading reports for the commit 0f6fd4b to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #83   +/-   ##
=======================================
  Coverage   98.54%   98.54%           
=======================================
  Files          14       14           
  Lines        1237     1239    +2     
  Branches      207      209    +2     
=======================================
+ Hits         1219     1221    +2     
  Misses         17       17           
  Partials        1        1           

Flag	Coverage Δ
unittests	98.54% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
python/rpdk/typescript/codegen.py	98.67% <0.00%> (+0.01%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.