Use better names for seed types

packages/ripple-address-codec/src/index.js

@@ -0,0 +1,30 @@
+var hashjs = require('hash.js');
+var apiFactory = require('x-address-codec');
+
+var NODE_PUBLIC = 28;
+var NODE_PRIVATE = 32;
+var ACCOUNT_ID = 0;
+var FAMILY_SEED = 33;
+var ED25519_SEED = [0x01, 0xE1, 0x4B];
+
+module.exports = apiFactory({
+  sha256: function (bytes) {
+    return hashjs.sha256().update(bytes).digest();
+  },
+  defaultAlphabet: 'ripple',
+  codecMethods: {
+    EdSeed : {
+      expectedLength: 16,
+      version: ED25519_SEED
+    },
+    Seed: {
+      versionTypes: ['ed25519', 'secp256k1'],
+      versions: [ED25519_SEED, FAMILY_SEED],
+      expectedLength: 16
+    },
+    AccountID: {version: ACCOUNT_ID },
+    NodePublic: {version: NODE_PUBLIC },
+    NodePrivate: {version: NODE_PRIVATE },
+    K256Seed : {version: FAMILY_SEED }
+  }
+});