rnano: add page (#16966)

Co-authored-by: Managor <42655600+Managor@users.noreply.github.com>

pages/common/rnano.md

@@ -0,0 +1,18 @@
+# rnano
+
+> A restricted version of `nano`.
+> Command-line text editor with restricted drive access.
+> See also: `nano`.
+> More information: <https://manned.org/rnano>.
+
+- Start the editor:
+
+`rnano`
+
+- Open a specific file:
+
+`rnano {{path/to/file}}`
+
+- Display help:
+
+`rnano {{[-h|--help]}}`