clicable image thumbnail

On my website easymde.min.js we placing small movie picture thumbnails, by default mouse click has no function but this code will open picture in a new window [](https://example.com/picture.jpg)
Would like insert image function https:// example.com/picture produce output [](https://example.com/picture.jpg)
Option to place clickable thumbnail that will show full size image preview upon mouse click

Start by tracing image insertion and preview behavior in easymde.min.js, using the linked Markdown image syntax as the expected input and output. Done means an inserted image can optionally render as a clickable thumbnail that opens the full-size image on click.

Written by the indexing model from the issue text.