Rename directory 'Unmaintained' back to 'archived'

Update text and links for archived plugins in README

archived/prometheus/test_prometheus.py

@@ -0,0 +1,40 @@
+import os
+from pyln.testing.fixtures import *  # noqa: F401,F403
+import urllib
+from ephemeral_port_reserve import reserve
+
+plugin_path = os.path.join(os.path.dirname(__file__), "prometheus.py")
+
+
+def test_prometheus_starts(node_factory):
+    l1 = node_factory.get_node()
+    # Test dynamically
+    l1.rpc.plugin_start(plugin_path)
+    l1.rpc.plugin_stop(plugin_path)
+    l1.rpc.plugin_start(plugin_path)
+    l1.stop()
+    # Then statically
+    l1.daemon.opts["plugin"] = plugin_path
+    l1.start()
+
+
+def test_prometheus_scrape(node_factory):
+    """Test that we can scrape correctly.
+    """
+    l1 = node_factory.get_node(options={'plugin': plugin_path})
+    scrape = urllib.request.urlopen("http://localhost:9750")
+    
+    
+    
+def test_prometheus_channels(node_factory):
+    port = reserve()
+    l1, l2, l3 = node_factory.line_graph(
+        3,
+        opts=[
+            {},
+            {'plugin': plugin_path, 'prometheus-listen': f'127.0.0.1:{port}'},
+            {}
+        ]
+    )
+    scrape = urllib.request.urlopen(f'http://localhost:{port}')
+    print(scrape)