builtin support currently for images - we have a command to insert a copied image into an asset folder and link to it in Dendron. we also have custom syntax for controlling image styling (https://wiki.dendron.so/notes/a91fd8da-6895-49fe-8164-a17acd...)
for other assets, we current recommend that you drop into the assets folder and link to them. vscode provides a bunch of extensions that let you preview different assets (eg. mp4, pdf, etc)
resizing can be done using our image syntax. eg. `{max-width: 300px}`. no support for cropping from inside dendron though I'm almost sure there's at least one vscode extension that can do that
i find embedding media especially screenshots to be getting more and more of an important aspect of note-taking.