It would be really useful for a user community to contribute to the
documentation that is generated using Doxygen, if the generated HTML output
contained direct links into e.g. the Bitbucket editor to the corresponding
source file. For example, when I have a generated HTML page showing the
documentation of a class X whose documentation is in a file X.hpp, the HTML
page should contain a link to an associated Bitbucket instance that allow to
directly edit X.hpp and create a pull request for that change.

This is analogous to what the new Microsoft documentation does. For example
https://docs.microsoft.com/en-us/cpp/build/reference/std-specify-language-
standard-version has a link to https://github.com/Microsoft/cpp-
docs/blob/master/docs/build/reference/std-specify-language-standard-
version.md

This should be pretty similar regardless of whether Bitbucket, GitHub or
GitLab (or something similar) is the target.