ci(yamllint): add YAML linting (#838)

[jlemesh]

Related to #836

Add YAML linting for all files except Helm chart files, which are linted by helm lint and ct lint (yamllint does not understand templating language and fails with invalid syntax errors).Update values-dev.yaml file to pass linter checks.

Add .editorconfig file with rules for various files. Adding also .go as I remember we were talking that it would be good if the file could be used everywhere, we'll be able to copypaste it to other repositories and there will be no need for changes if new files are introduced to the repository. Let me know if it is better to only add config only for the files that currently exist in the repository.

For markdownlint, some rules were disabled because there will be to many changes to existing files (e. g. line length). Some rules do not work due to some specific contents in files, e. g. we have cron schedule defined (* * * * *) and markdownlint thinks this is emphasis (bold) and throws warning that there is a space between emphasis asterisks.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 29.80%. Comparing base (0c0849d) to head (d4df666).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #838   +/-   ##
=======================================
  Coverage   29.80%   29.80%           
=======================================
  Files          26       26           
  Lines        2486     2486           
=======================================
  Hits          741      741           
  Misses       1745     1745