Add more details to README.md

Signed-off-by: doxiao <[email protected]>

Author: doxiao

kubernetes/samples/scripts/create-weblogic-domain/domain-home-in-image/README.md

@@ -8,7 +8,7 @@ The following prerequisites must be handled prior to running the create domain s
 * Make sure the WebLogic operator is running.
 * Create a Kubernetes namespace for the domain unless the intention is to use the default namespace.
 * Create the Kubernetes secrets `username` and `password` of the admin account in the same Kubernetes namespace as the domain.
-* Build the Oracle WebLogic image `oracle/weblogic:12.2.1.3-developer`. Refer to [Oracle WebLogic Server on Docker](https://github.com/oracle/docker-images/tree/master/OracleWebLogic/dockerfiles/12.2.1.3).
+* Build the Oracle WebLogic image `oracle/weblogic:12.2.1.3-developer`. Refer to [Oracle WebLogic Server on Docker](https://github.com/oracle/docker-images/tree/master/OracleWebLogic/dockerfiles/12.2.1.3). If a different `baseImage` (see Configuration table below) is specified, the specified image needs to be built locally or pulled from a repository.
 
 ## Use the script to create a domain
 
@@ -68,7 +68,7 @@ The following parameters can be provided in the inputs file.
 | `adminPort` | Port number for the Administration Server inside the Kubernetes cluster. | `7001` |
 | `adminNodePort` | Port number of the Administration Server outside the Kubernetes cluster. | `30701` |
 | `adminServerName` | Name of the Administration Server. | `admin-server` |
-| `baseImage` | The image that is used to build the domain-home-in-image Docker image. If not specified, use the built-in base image `oracle/weblogic:12.2.1.3-developer`. | `oracle/weblogic:12.2.1.3-developer` |
+| `baseImage` | The image that is used to build the domain-home-in-image Docker image. If not specified, use the built-in base image `oracle/weblogic:12.2.1.3-developer`. The image specified here needs to be built locally or pulled from a repository before the `create-domain.sh` script is executed. | `oracle/weblogic:12.2.1.3-developer` |
 | `clusterName` | Name of the WebLogic cluster instance to generate for the domain. | `cluster-1` |
 | `clusterType` | Type of the WebLogic Cluster. Legal values are `CONFIGURED` or `DYNAMIC`. | `DYNAMIC` |
 | `configuredManagedServerCount` | Number of Managed Server instances to generate for the domain. | `2` |