In-word expansion (equivalent to Ultisnips i)

[jghauser]

I'm not sure whether this is already possible. If so, then this is a question about how to do it; if it isn't possible, it's a suggestion for a new feature.

Ultisnips allows in-word expansion. Here's how they describe it:

i In-word expansion - By default a snippet is expanded only if the tab
trigger is the first word on the line or is preceded by one or more
whitespace characters. A snippet with this option is expanded
regardless of the preceding character. In other words, the snippet can
be triggered in the middle of a word.

I use this a lot to insert comments in markdown files. For instance I will write This is a randomcm and then expand the cm snippet to get This is a random<!-- comment here -->. It would be great if I could do the same in snippets.nvim!