Add .env.example

[wslulciuc]

This PR adds .env.example that can be used to created a .env file to override variables defined in our docker-compose files.

[codecov]

Codecov Report

Merging #1631 (fcfef45) into main (27ad186) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main    #1631   +/-   ##
=========================================
  Coverage     78.17%   78.17%           
  Complexity      980      980           
=========================================
  Files           196      196           
  Lines          5238     5238           
  Branches        417      417           
=========================================
  Hits           4095     4095           
  Misses          696      696           
  Partials        447      447           

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