Add features

nep-15.mediawiki

@@ -31,8 +31,9 @@ The NeoContract Manifest is defined by JSON format, which has the following basi
 <pre>
 
 {
-  "name":"",
+  "name": "",
   "groups": [],
+  "features": [],
   "supportedstandards": [],
   "abi": {},
   "permissions": [],
@@ -46,6 +47,8 @@ The <code>name</code> is the name of the contract, which can be any valid identi
 
 The <code>groups</code> field is an array of <code>Group</code> objects which represent a set of mutually trusted contracts. A contract will trust and allow any contract in the same group to invoke it, and the user interface will not give any warnings.
 
+The <code>features</code> field will be used for future expansion and should always be an empty array for now.
+
 The <code>supportedstandards</code> field describes the [[obsolete/nep-10.mediawiki|NEP-10]] values.
 
 The <code>abi</code> field describes which methods and events are included in the contract and how other contracts interact with them. For technical details of ABI, please refer to [https://github.com/neo-project/proposals/pull/119 NEP-14: NeoContract ABI].