[misc] Add more shields in README

[vkarak]

I have also updated a bit the layout of the shields.

[teojgo]

The line here has to be changed as well since it gets the content from the README and it should not include the badges.

[codecov-io]

Codecov Report

Merging #1122 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1122   +/-   ##
=======================================
  Coverage   91.89%   91.89%           
=======================================
  Files          81       81           
  Lines       11626    11626           
=======================================
  Hits        10684    10684           
  Misses        942      942

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