Add new file

doc/api/leases-reclaim.json

+{
+    "name": "leases-reclaim",
+    "brief": "The leases-reclaim command instructs the server to reclaim all expired leases immediately.",
+    "description": "See <xref linkend=\"leases-reclaim\"/>",
+    "support": [ "kea-dhcp4", "kea-dhcp6" ],
+    "avail": "1.0.0",
+    "cmd-syntax": "{
+    \"command\": \"leases-reclaim\",
+    \"arguments\": {
+        \"remove\": true
+    }
+}",
+}
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