Update extensions in README.md

Author: lordgamez

README.md

@@ -75,6 +75,7 @@ The next table outlines CMAKE flags that correspond with MiNiFi extensions. Exte
 | AWS                              | [AWSCredentialsService](CONTROLLERS.md#awscredentialsservice)<br/>[PutS3Object](PROCESSORS.md#puts3object)<br/>[DeleteS3Object](PROCESSORS.md#deletes3object)<br/>[FetchS3Object](PROCESSORS.md#fetchs3object)<br/>[ListS3](PROCESSORS.md#lists3)                                                                                                                                                                                                                                                                                                                                                                                               | -DENABLE_AWS=ON              |
 | Azure                            | [AzureStorageCredentialsService](CONTROLLERS.md#azurestoragecredentialsservice)<br/>[PutAzureBlobStorage](PROCESSORS.md#putazureblobstorage)<br/>[DeleteAzureBlobStorage](PROCESSORS.md#deleteazureblobstorage)<br/>[FetchAzureBlobStorage](PROCESSORS.md#fetchazureblobstorage)<br/>[ListAzureBlobStorage](PROCESSORS.md#listazureblobstorage)<br/>[PutAzureDataLakeStorage](PROCESSORS.md#putazuredatalakestorage)<br/>[DeleteAzureDataLakeStorage](PROCESSORS.md#deleteazuredatalakestorage)<br/>[FetchAzureDataLakeStorage](PROCESSORS.md#fetchazuredatalakestorage)<br/>[ListAzureDataLakeStorage](PROCESSORS.md#listazuredatalakestorage) | -DENABLE_AZURE=ON            |
 | CivetWeb                         | [ListenHTTP](PROCESSORS.md#listenhttp)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | -DENABLE_CIVET=ON            |
+| Couchbase                        | [PutCouchbaseKey](PROCESSORS.md#putcouchbasekey)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | -DENABLE_COUCHBASE=ON        |
 | Elasticsearch                    | [ElasticsearchCredentialsControllerService](CONTROLLERS.md#elasticsearchcredentialscontrollerservice)<br/>[PostElasticsearch](PROCESSORS.md#postelasticsearch)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | -DENABLE_ELASTICSEARCH=ON    |
 | ExecuteProcess (Linux and macOS) | [ExecuteProcess](PROCESSORS.md#executeprocess)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | -DENABLE_EXECUTE_PROCESS=ON  |
 | Google Cloud Platform            | [DeleteGCSObject](PROCESSORS.md#deletegcsobject)<br>[FetchGCSObject](PROCESSORS.md#fetchgcsobject)<br>[GCPCredentialsControllerService](CONTROLLERS.md#gcpcredentialscontrollerservice)<br>[ListGCSBucket](PROCESSORS.md#listgcsbucket)<br>[PutGCSObject](PROCESSORS.md#putgcsobject)                                                                                                                                                                                                                                                                                                                                                           | -DENABLE_GCP=ON              |