add missing version of nu_plugin_clipboard (#87)

related to
- #86 

## Description
uses [one of the latest commits of
`nu_plugin_clipboard`](FMotalleb/nu_plugin_clipboard@98d7102)
as the anchor point to install a version compatible with Nushell 0.92.

> **Important**
> this will likely create a conflict with #86 but i wanted to have that
plugin added, it's too useful 😉

registry.nuon

@@ -54,6 +54,13 @@
             "2cd2a67",
             .
         ],
+        [
+            nu_plugin_clipboard,
+            "0.92.1",
+            "https://github.com/FMotalleb/nu_plugin_clipboard",
+            "98d7102",
+            .
+        ],
         [
             nu_plugin_desktop_notifications,
             "1.0.7",