Cleaning up the plugin instance, and adding more comments

[AnujRNair]

Summary

Cleaning up the plugin instance by referencing the instance variables for the policy, and the user defined policy, and adding more comments so it's easier to follow along with what the code is doing

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've written tests to cover the new code and functionality included in this PR.
• I've read, agree to, and signed the Contributor License Agreement (CLA).

[codecov]

Codecov Report

Merging #25 into master will decrease coverage by 0.24%.
The diff coverage is 100%.

@@ Coverage Diff @@ ## master #25 +/- ## ========================================= - Coverage 93.75% 93.5% -0.25%  ========================================= Files 2 2 Lines 80 77 -3 Branches 11 11 ========================================= - Hits 75 72 -3  Misses 4 4 Partials 1 1

Impacted Files	Coverage Δ
plugin.js	91.07% <100%> (-0.46%)	⬇️

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