cfg: adds info about local img uploader to docs

conf/sample.ini

@@ -417,7 +417,7 @@ log_queries =
 #################################### External image storage ##########################
 #################################### External image storage ##########################
 [external_image_storage]
 [external_image_storage]
 # Used for uploading images to public servers so they can be included in slack/email messages.
 # Used for uploading images to public servers so they can be included in slack/email messages.
-# you can choose between (s3, webdav, gcs, azure_blob)
+# you can choose between (s3, webdav, gcs, azure_blob, local)
 ;provider =
 ;provider =
 
 
 [external_image_storage.s3]
 [external_image_storage.s3]
@@ -442,3 +442,6 @@ log_queries =
 ;account_name =
 ;account_name =
 ;account_key =
 ;account_key =
 ;container_name =
 ;container_name =
+
+[external_image_storage.local]
+# does not require any configuration

docs/sources/installation/configuration.md

@@ -766,7 +766,7 @@ Time to live for snapshots.
 These options control how images should be made public so they can be shared on services like slack.
 These options control how images should be made public so they can be shared on services like slack.
 
 
 ### provider
 ### provider
-You can choose between (s3, webdav, gcs, azure_blob). If left empty Grafana will ignore the upload action.
+You can choose between (s3, webdav, gcs, azure_blob, local). If left empty Grafana will ignore the upload action.
 
 
 ## [external_image_storage.s3]
 ## [external_image_storage.s3]