rewrite source paths for extracted raster images

[pkra]

We currently rewrite image sources (for raster images extracted from SVG) further downstream (e.g., ams-html, ams-bookhtml).

We should consider doing so here.

[pkra]

This should probably be done by extending the image alt dictionary

texml-to-html/texml-to-html.js

Line 10 in d1d539d

* @param {Object} imageAltDictionary - Key value store with file names and alt text strings

That would likely end up a breaking change.

[pkra]

It would help avoid duplication downstream. (However, books also have an adjustment for the folder structure; I'm not sure if that part would make sense here.)

[pkra]

Marking this as upstream since we'd need something to generate path adjustments and pass them to texml-to-html.

[pkra]

"upstream" here means "whatever calls texml-to-html" (i.e., not texml).