docs: Add multiaccount scan in docs (#1554)

docs/tutorials/aws/multiaccount.md

@@ -0,0 +1,65 @@
+# Scan Multiple AWS Accounts
+
+Prowler can scan multiple accounts when it is ejecuted from one account that can assume a role in those given accounts to scan using [Assume Role feature](role-assumption.md) and [AWS Organizations integration feature](organizations.md).
+
+
+## Scan multiple specific accounts sequentially
+
+- Declare a variable with all the accounts to scan:
+
+```
+ACCOUNTS_LIST='11111111111 2222222222 333333333'
+```
+
+- Then run Prowler to assume a role (change `<role_name>` below to yours, that must be the same in all accounts):
+
+```
+ROLE_TO_ASSUME=<role_name>
+  for accountId in $ACCOUNTS_LIST; do
+  prowler aws --role arn:aws:iam::$accountId:role/$ROLE_TO_ASSUME
+done
+```
+
+## Scan multiple specific accounts in parallel
+
+- Declare a variable with all the accounts to scan:
+
+```
+ACCOUNTS_LIST='11111111111 2222222222 333333333'
+```
+
+- Then run Prowler to assume a role (change `<role_name>` below to yours, that must be the same in all accounts), in this example it will scan 3 accounts in parallel:
+
+```
+ROLE_TO_ASSUME=<role_name>
+PARALLEL_ACCOUNTS="3"
+for accountId in $ACCOUNTS_LIST; do
+    test "$(jobs | wc -l)" -ge $PARALLEL_ACCOUNTS && wait || true
+    {
+        prowler aws --role arn:aws:iam::$accountId:role/$ROLE_TO_ASSUME
+    } &
+done
+```
+
+## Scan mutiple accounts from AWS Organizations in parallel
+
+- Declare a variable with all the accounts to scan. To do so, get the list of your AWS accounts in your AWS Organization by running the following command (will create a variable with all your ACTIVE accounts). Remember to run that command with the permissions needed to get that information in your AWS Organizations Management account.
+
+```
+ACCOUNTS_IN_ORG=$(aws organizations list-accounts --query Accounts[?Status==`ACTIVE`].Id --output text)
+```
+
+- Then run Prowler to assume a role (change `<role_name>` that must be the same in all accounts and `<management_organizations_account_id>` that must be your AWS Organizations management account ID):
+
+```
+ROLE_TO_ASSUME=<role_name>
+MGMT_ACCOUNT_ID=<management_organizations_account_id>
+PARALLEL_ACCOUNTS="3"
+for accountId in $ACCOUNTS_IN_ORG; do
+    test "$(jobs | wc -l)" -ge $PARALLEL_ACCOUNTS && wait || true
+    {
+        prowler aws --role arn:aws:iam::$accountId:role/$ROLE_TO_ASSUME \
+        --organizations-role arn:aws:iam::$MGMT_ACCOUNT_ID:role/$ROLE_TO_ASSUME
+    } &
+done
+```

mkdocs.yml

@@ -41,6 +41,7 @@ nav:
           - Assume Role: tutorials/aws/role-assumption.md
           - AWS Security Hub: tutorials/aws/securityhub.md
           - AWS Organizations: tutorials/aws/organizations.md
+          - Scan Multiple AWS Accounts: tutorials/aws/multiaccount.md
         - Azure:
           - Authentication: tutorials/azure/authentication.md
           - Subscriptions: tutorials/azure/subscriptions.md