* Add a recipe for qpdf.el
`orgtre/qpdf.el` is a transient wrapper over `qpdf/qpdf`, allowing you
to execute PDF transformation commands from inside Emacs
* Update the recipe for pdf-tools
- Raise the minimum supported Emacs version
- Remove unnecessary clauses
Closes: dimitri/el-get#2860
* Rename emacs-tree-sitter to elisp-tree-sitter
This is the new name of the repo.
Also, point it to the upstream package.
