docs(readme): mention --pass and ipfs.key...

README.md

@@ -194,6 +194,8 @@ const node = new IPFS({
   // },
   start: true, // default
   // start: false,
+  pass: '' // default
+  // pass: 'pass phrase for key access',
   EXPERIMENTAL: { // enable experimental features
     pubsub: true,
     sharding: true, // enable dir sharding
@@ -268,6 +270,14 @@ A complete API definition is in the works. Meanwhile, you can learn how to you u
   - [`ipfs.object.patch.setData(multihash, data, [options, callback])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/OBJECT.md#objectpatchsetdata)
 - [pin (not implemented, yet!)](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/)
 
+#### `Security`
+
+- [key](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/KEY.md)
+  - `ipfs.key.gen(name, options, [callback])`
+  - `ipfs.key.list([callback])`
+  - `ipfs.key.rename(oldName, newName, [callback])`
+  - `ipfs.key.rm(name, [callback])`
+
 #### `Network`
 
 - [bootstrap](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/)