Add further linter files

[brainelectronics]

Added

• .editorconfig for common editor settings, see Add other linter files #12
• .yamllint to lint all used YAML files, see Add other linter files #12
• codecov.yaml to specify further settings and limits for the coverage
• yamllint package to the requirements-test.txt file
• Run YAML linter on test workflow

Changed

• Fixed uncovered YAML syntax issues in all workflow files
• Removed unused files from .gitignore file

[codecov-commenter]

Codecov Report

Merging #13 (56a9975) into main (8f3cb91) will not change coverage.
The diff coverage is n/a.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@            Coverage Diff            @@
##              main       #13   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            3         3           
  Lines           14        14           
  Branches         1         1           
=========================================
  Hits            14        14           

Flag	Coverage Δ
unittests	100.00% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[brainelectronics]

LGTMyself