updated getAllCIClasses read me for better documentation (#2214)

Author: ChaseMillers

Server-Side Components/Background Scripts/Get All the CI classes/README.md

@@ -1 +1,17 @@
-This background script provides the names of all the available Ci classes present in the system
+# Get All CI Classes
+
+A background script that lists all Configuration Item (CI) classes in your ServiceNow instance by using the TableUtils API to find all tables that extend `cmdb_ci`.
+
+## Usage
+
+1. Navigate to **System Definition → Scripts - Background**
+2. Copy and paste the script content
+3. Click "Run fix script"
+
+## What It Does
+
+The script:
+1. Creates a TableUtils object for the base CI table (`cmdb_ci`)
+2. Gets all tables that extend this base class using `getAllExtensions()`
+3. Converts the Java object to JavaScript array using `j2js()`
+4. Prints each CI class table name