Doc follow up (#693)

* Restored target environments link; rename Tools Configuration page

* Removed configuration pages that were combined to tool_configuration.md; correct some links

* Removed sample pages that were combined to use_cases.md

* Changed use case to refer to standalone page that is shared with Extract Tool

Author: rakillen

README.md

@@ -36,7 +36,7 @@ For the supported WebLogic Server and JDK versions required to run WebLogic Serv
 - [The Model](site/model.md)
 - [The Archive File](site/archive.md)
 - [Model Use Cases](site/use_cases.md)
-- [Tool Configuration](site/tool_configuration.md)
+- [Tools Configuration](site/tool_configuration.md)
 
 ## Developer Guide
 

site/admin_server.md

@@ -1,9 +1,9 @@
 ## Target Environments
 
 The [Discover Domain](../discover.md) and [Prepare Model](../prepare.md) Tools allow you to customize the model and other files produced to be compatible with a specific target environment. Options for a target environment may include:
-- Using model tokens for some attributes in the model (see [Model Tokens](../../README.md#model-tokens))
+- Using model tokens for some attributes in the model (see [Model Tokens](../model.md#model-tokens))
 - Using Kubernetes secrets for credentials in the model
-- Applying filters to the model (see [Model Filters](../tool_filters.md))
+- Applying filters to the model (see [Model Filters](../tool_configuration.md#model-filters))
 - Creating additional configuration files for the target system
 
 ### Specifying a Target Environment
@@ -28,7 +28,7 @@ The `<target-name>` value corresponds to the value of the `-target` argument on
  - [Oracle Weblogic Server Kubernetes Operator](#the-oracle-weblogic-server-kubernetes-operator-target) (named `k8s`)
  - [Verrazzano](#the-verrazzano-target) (named `vz`). 
 
-You can define a new or extended target environment with a new `target-name` in the above location, or using a [Custom Configuration](custom_configuration.md) directory, such as `$WDT_CUSTOM_CONFIG/target/<my-target-name>/target.json`. 
+You can define a new or extended target environment with a new `target-name` in the above location, or using a [Custom Configuration](../tool_configuration.md#custom-configuration) directory, such as `$WDT_CUSTOM_CONFIG/target/<my-target-name>/target.json`. 
 
 Here is an example of a target environment file:
 ```
@@ -48,7 +48,7 @@ Each of the fields in this example is optional, and can be customized.
 
 #### `model_filters`
 
-This field specifies the filters to be applied to the resulting model. This follows the same format and rules as the [Model Filters](../tool_filters.md) configuration. The `discover` type should always be used here.
+This field specifies the filters to be applied to the resulting model. This follows the same format and rules as the [Model Filters](../tool_configuration.md#model-filters) configuration. The `discover` type should always be used here.
 
 The `@@TARGET_CONFIG_DIR@@` token can be used to indicate that the specified filter is in the same directory as the target configuration file.