Docs improvements for wait feature. (#2354)

Docs improvements for  wait feature of `kubernetes_manifest`
---------

Co-authored-by: Brian McClain <brianmmcclain@gmail.com>

website/docs/r/manifest.html.markdown

@@ -223,7 +223,8 @@ The following arguments are supported:
 - `computed_fields` - (Optional) List of paths of fields to be handled as "computed". The user-configured value for the field will be overridden by any different value returned by the API after apply.
 - `manifest` (Required) An object Kubernetes manifest describing the desired state of the resource in HCL format.
 - `object` (Optional) The resulting resource state, as returned by the API server after applying the desired state from `manifest`.
-- `wait_for` (Optional) An object which allows you configure the provider to wait for certain conditions to be met. See below for schema. **DEPRECATED: use `wait` block**.
+- `wait` (Optional) An object which allows you configure the provider to wait for specific fields to reach a desired value or certain conditions to be met. See below for schema.
+- `wait_for` (Optional, Deprecated) An object which allows you configure the provider to wait for certain conditions to be met. See below for schema. **DEPRECATED: use `wait` block**.
 - `field_manager` (Optional) Configure field manager options. See below.
 
 ### `wait`
@@ -232,7 +233,26 @@ The following arguments are supported:
 
 - `rollout` (Optional) When set to `true` will wait for the resource to roll out, equivalent to `kubectl rollout status`. 
 - `condition` (Optional) A set of condition to wait for. You can specify multiple `condition` blocks and it will wait for all of them. 
-- `fields` (Optional) A map of fields and a corresponding regular expression with a pattern to wait for. The provider will wait until the field matches the regular expression. Use `*` for any value. 
+- `fields` (Optional) A map of field paths and a corresponding regular expression with a pattern to wait for. The provider will wait until the field's value matches the regular expression. Use `*` for any value.
+
+A field path is a string that describes the fully qualified address of a field within the resource, including its parent fields all the way up to "object". The syntax of a path string follows the rules below:
+  * Fields of objects are addressed with `.`
+  * Keys of a map field are addressed with `["<key-string>"]`
+  * Elements of a list or tuple field are addresed with `[<index-numeral>]`
+
+  The following example waits for Kubernetes to create a ServiceAccount token in a Secret, where the `data` field of the Secret is a map.
+  ```hcl
+  wait {
+    fields = {
+      "data[\"token\"]" = ".+"
+    }
+  }
+  ```
+  You can use the [`type()`]() Terraform function to determine the type of a field. With the resource created and present in state, run `terraform console` and then the following command:
+  ```hcl
+  > type(kubernetes_manifest.my-secret.object.data)
+    map(string)
+  ```
 
 ### `wait_for` (deprecated, use `wait`)