add docs

x/accounts/README.md

@@ -1,3 +1,44 @@
 # x/accounts
 
-The x/accounts module provides module and facilities for writing smart cosmos-sdk accounts.
+The x/accounts module provides module and facilities for writing smart cosmos-sdk accounts.
+
+# Genesis
+
+## Creating accounts on genesis
+
+In order to create accounts at genesis, the `x/accounts` module allows developers to provide
+a list of genesis `MsgInit` messages that will be executed in the `x/accounts` genesis flow.
+
+This follows the same initialization flow and rules that would happen if the chain is running. 
+The only concrete difference is that this is happening at the genesis block.
+
+For example, given the following `genesis.json` file:
+
+```json
+{
+  "app_state": {
+    "accounts": {
+      "init_account_msgs": [
+        {
+          "sender": "account_creator_address",
+          "account_type": "lockup",
+          "message": {
+            "@type": "cosmos.accounts.defaults.lockup.MsgInitLockupAccount",
+            "owner": "some_owner",
+            "end_time": "..",
+            "start_time": ".."
+          },
+          "funds": [
+            {
+              "denom": "stake",
+              "amount": "1000"
+            }
+          ]
+        }
+      ]
+    }
+  }
+}
+```
+
+The accounts module will run the lockup account initialization message.