Replace broken ImagePlot download link in introduccion-a-imageplot-y-la-visualizacion-de-metadatos

[anisa-hawes]

• [x] I am replacing a broken link in the ES lesson Introducción a ImagePlot y la visualización de metadatos de colecciones de imágenes. The problem link flagged as failed is https://imagej.nih.gov/ij/? which has been moved to https://imagej.net/.

• [x] Meanwhile, I noticed that links to the Software Studies Initiative http://lab.softwarestudies.com/ are also failing, and we have replaced this with the new URL http://lab.culturalanalytics.info/

• [ ] The download link to ImagePlot is no longer available http://lab.softwarestudies.com/p/imageplot.html#download. There are no Releases available on the tool's GitHub https://github.com/culturevis/imageplot, so we are seeking insight into whether the software is still available, and still functional.