oniux: add page (#16738)

Co-authored-by: Dylan <145150333+dmmqz@users.noreply.github.com>

pages/linux/oniux.md

@@ -0,0 +1,25 @@
+# oniux
+
+> Isolate an arbitrary application and route traffic over the Tor network.
+> Note: This is experimental software.
+> More information: <https://gitlab.torproject.org/tpo/core/oniux>.
+
+- Isolate an application:
+
+`oniux {{command}}`
+
+- Query a website:
+
+`oniux curl {{https://example.com}}`
+
+- Query an onion site:
+
+`oniux curl {{http://example.onion}}`
+
+- Run an entire shell in "torified" isolation:
+
+`oniux bash`
+
+- Isolate graphical applications in desktop environments:
+
+`oniux hexchat`