pandoc-plot: download ældre versioner

## Release 1.9.2

• Added a `build_directory` configuration option to override the directory where temporary rendering scripts are written. This is useful for sandboxed renderers (e.g. `mmdc` installed via `snap` on Linux) that cannot access the system temporary directory (#82).
• Fixed an issue where TeX output contained a figure even if the caption was empty (#37).
• Fixed a documentation issue where the null command-line arguments for `plantuml` should have been `""` (#76).

Release 1.9.1
- Fixed an issue where extra parameters were not passed down to pandoc, depending on the output format (#38).

Release 1.7.0
- Added support for the declarative diagram language D2, thanks to a contribution by Sanchayan Maity (#60).
- Added support for optparse-applicative v0.18.