Improve readme file

[frandbf]

What this PR does / why we need it:

Improves the readability of the readme file and adds a link to the documentation

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[codecov-io]

Codecov Report

Merging #2431 into master will decrease coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2431      +/-   ##
==========================================
- Coverage   41.37%   41.31%   -0.06%     
==========================================
  Files          74       74              
  Lines        5262     5262              
==========================================
- Hits         2177     2174       -3     
- Misses       2789     2791       +2     
- Partials      296      297       +1

Impacted Files	Coverage Δ
cmd/nginx/main.go	21.37% <0%> (-2.07%)	⬇️

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[aledbf]

/approve

[aledbf]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, frandbf

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[aledbf]

@frandbf thanks!