missing creating-packages doc file

[birbilis]

at https://github.com/DelphiPackageManager/DPM/blame/master/docs/concepts/how-it-works.md there is a broken link to creating-packages.md (it is missing)

but I wonder if the docs folder there is up to date, since there's a doc repository that is separate (https://github.com/DelphiPackageManager/docs) and which must contain creating-packages since it generates https://docs.delphi.dev/getting-started/creating-packages.html fine