Replace legacy `save_missing` mentions with `save_report`

docs/home/guides/kubernetes.md

@@ -149,7 +149,7 @@ data:
       show_options: false
       show_missing: true
       show_missing_assets: true
-      save_missing: true
+      save_report: true
       tvdb_language: eng
       ignore_ids:
       ignore_imdb_ids:

docs/metadata/overlay.md

@@ -409,7 +409,7 @@ Builders use third-party services to source items for overlays. Multiple builder
 
 ## Details
 
-Only a few details can be used with overlays: `limit`, `show_missing`, `save_missing`, `missing_only_released`, `minimum_items`, `cache_builders`, `tmdb_region`
+Only a few details can be used with overlays: `limit`, `show_missing`, `save_report`, `missing_only_released`, `minimum_items`, `cache_builders`, `tmdb_region`
 
 * [Setting Details](details/setting)
 * [Metadata Details](details/metadata)