add documentation

changelog.txt

@@ -1,6 +1,7 @@
 jc changelog
 
 2019xxxx v1.1.1
+- Add arp parser
 - Add dig parser
 - Add nslookup parser
 - Add unit tests

jc/parsers/arp.py

@@ -6,7 +6,22 @@ Usage:
 Example:
 
 $ arp | jc --arp -p
-
+[
+  {
+    "address": "gateway",
+    "hwtype": "ether",
+    "hwaddress": "00:50:56:f7:4a:fc",
+    "flags_mask": "C",
+    "iface": "ens33"
+  },
+  {
+    "address": "192.168.71.254",
+    "hwtype": "ether",
+    "hwaddress": "00:50:56:fe:7a:b4",
+    "flags_mask": "C",
+    "iface": "ens33"
+  }
+]
 """