Add 3D Objects Counter - StarDist plugin page

[Jay2owe]

Adds a public ImageJ wiki page for 3D Objects Counter - StarDist and its active update site.

The page documents:

• StarDist detection on each Z slice and TrackMate LAP linking into measured 3D objects
• installation and the pinned first-run StarDist runtime installer
• the released v0.1.0 dialog controls and supported inputs
• full-shape label/object maps, measurements, and object-count reporting
• recursive batch processing, regex grouping, output folders, and manifests
• macro/headless use, Java API, limitations, and citations

Validation:

• drafted from the v0.1.0 source, UI labels, release documentation, and update-site metadata
• front matter parses as YAML and contains the active source/update-site/version metadata
• public project, ImageJ, update-site, and citation links were checked
• no existing page or open duplicate PR was found

Local Jekyll execution was not available because Ruby is not installed; GitHub's Jekyll workflow provides the authoritative build check.