Add packageRules to ignore eslint

[tomvothecoder]

This PR adds packageRules to ignore eslint since updating to new major versions can break compatibility with existing packages (e.g. react-scripts).

Specifically, upgrading to eslint v.7.x breaks compatibility with react-scripts 3.x.

Related Issues:

• Support ESLint 7.x facebook/create-react-app#8978

[codecov]

Codecov Report

Merging #117 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #117   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           50        50           
  Lines         1029      1029           
  Branches       153       153           
=========================================
  Hits          1029      1029           

Flag	Coverage Δ
#backend	100.00% <ø> (ø)
#frontend	100.00% <ø> (ø)

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