Merge branch 'master' into 30-clearify-git-cz-keywords

technical-reference-main.txt

+chapters/about.md
+chapters/explanatory-notes.md
+chapters/style-guides.md
+chapters/documentation.md
+chapters/version-control.md
+chapters/bug-tracking.md
+chapters/software-tests.md
+chapters/build-ci.md
+chapters/deployment-maintenance.md
+chapters/code-quality.md
+chapters/intellectual-property.md
+chapters/retirement.md
+chapters/cessda-decisions.md
+chapters/links.md
+chapters/onboarding.md