docs: add note for tablename customization

Author: kenjis

docs/install.md

@@ -74,6 +74,10 @@ Require it with an explicit version constraint allowing its desired stability.
     php spark shield:setup
     ```
 
+    > **Note** If you want to customize table names, you must change the table names
+    > before running database migrations.
+    > See [Customizing Shield](./customization.md#custom-table-names).
+
 2. Configure **app/Config/Email.php** to allow Shield to send emails with the [Email Class](https://codeigniter.com/user_guide/libraries/email.html).
 
     ```php
@@ -145,6 +149,10 @@ your project.
 
 5. **Migration** Run the migrations.
 
+    > **Note** If you want to customize table names, you must change the table names
+    > before running database migrations.
+    > See [Customizing Shield](./customization.md#custom-table-names).
+
     ```console
     php spark migrate --all
     ```
@@ -278,4 +286,4 @@ public $globals = [
     ]
 ]
 ```
-The same should apply for the Rate Limiting and Forcing Password Reset.
+The same should apply for the Rate Limiting and Forcing Password Reset.