The Debian packaging of taxy-magit-section-el is maintained in git, using the
merging workflow described in dgit-maint-merge(7).  There isn't a patch queue
that can be represented as a quilt series.

A detailed breakdown of the changes is available from their canonical
representation - git commits in the packaging repository.  For example, to see
the changes made by the Debian maintainer in the first upload of upstream
version 1.2.3, you could use:

    % git clone https://git.dgit.debian.org/taxy-magit-section-el
    % cd taxy-magit-section-el
    % git log --oneline 1.2.3..debian/1.2.3-1 -- . ':!debian'

(If you have dgit, use `dgit clone taxy-magit-section-el`, rather than plain
`git clone`.)

A single combined diff, containing all the changes, follows.
