Add documentation for new PKI certificate count census metrics (#1106)

Author: rculpepper

content/vault/v1.21.x (rc)/content/docs/license/product-usage-reporting.mdx

@@ -170,7 +170,7 @@ All of these metrics are numerical, and contain no sensitive values or additiona
 | `vault.secret.engine.alicloud.count`                                | The total number of Alicloud secret engines in Vault.                                                            |
 | `vault.secret.engine.aws.count`                                     | The total number of AWS secret engines in Vault.                                                                 |
 | `vault.secret.engine.aws.dynamic.role.count`                        | The total number of AWS dynamic roles in Vault.                                                            |
-| `vault.secret.engine.aws.static.role.count`                         | The total number of AWS static roles in Vault. 
+| `vault.secret.engine.aws.static.role.count`                         | The total number of AWS static roles in Vault.
 | `vault.secret.engine.azure.count`                                   | The total number of Azure secret engines in Vault.                                                               |
 | `vault.secret.engine.azure.dynamic.role.count`                      | The total number of Azure dynamic roles in Vault.                                                          |
 | `vault.secret.engine.consul.count`                                  | The total number of Consul secret engines in Vault.                                                              |
@@ -254,6 +254,8 @@ All of these metrics are numerical, and contain no sensitive values or additiona
 | `vault.autosnapshots.google-gcs.count`                              | The total of automated snapshot configurations with storage type Google GCS.                                     |
 | `vault.autosnapshots.aws-s3.count`                                  | The total number of automated snapshot configurations with storage type AWS S3.                                  |
 | `vault.autosnapshots.azure-blob.count`                              | The total number of automated snapshot configurations with storage type Azure Blob.                              |
+| `vault.pki.cert.stored.count.current_month                          | The number of certificates stored in built-in PKI backends in the current month.                                 |
+| `vault.pki.cert.stored.count.previous_month                         | The number of certificates stored in built-in PKI backends in the previous month.                                |
 
 ## Usage metadata list
 

content/vault/v1.21.x (rc)/content/docs/license/utilization/manual-reporting.mdx

@@ -184,6 +184,16 @@ The default retention period is 400 days.
       "key": "clientcount.previous_month_complete.type.secret_sync",
       "value": 0,
       "mode": "write"
+    },
+    "certcount.current_month_estimate": {
+      "key": "certcount.current_month_estimate",
+      "value": 0,
+      "mode": "write"
+    },
+    "certcount.previous_month_complete": {
+      "key": "certcount.previous_month_complete",
+      "value": 0,
+      "mode": "write"
     }
   },
   "product_version": "1.16.0+ent",