Add a link to raindrop preview

[mbovo]

Would be awesome to have a link to raindrop preview: the url should be something like https://app.raindrop.io/my/0/highlights:true/item/$ID/preview in both single page and multiple pages import

Use cases:

• Having the possibility to open the raindrop app and change/add highlights directly from logseq import

[mbovo]

Not a typescript developer but I'm trying to look at code and prepare a PR for this, wdyt @phildenhoff ?