Fix typo in spec page (apache#4882)

format/spec.md

@@ -491,7 +491,7 @@ A snapshot consists of the following fields:
 | _optional_ | _optional_ | **`parent-snapshot-id`** | The snapshot ID of the snapshot's parent. Omitted for any snapshot with no parent |
 |            | _required_ | **`sequence-number`**    | A monotonically increasing long that tracks the order of changes to a table |
 | _required_ | _required_ | **`timestamp-ms`**       | A timestamp when the snapshot was created, used for garbage collection and table inspection |
-| _optional_ | _required_ | **`manifest-list`**      | The location of a manifest list for this snapshot that tracks manifest files with additional meadata |
+| _optional_ | _required_ | **`manifest-list`**      | The location of a manifest list for this snapshot that tracks manifest files with additional metadata |
 | _optional_ |            | **`manifests`**          | A list of manifest file locations. Must be omitted if `manifest-list` is present |
 | _optional_ | _required_ | **`summary`**            | A string map that summarizes the snapshot changes, including `operation` (see below) |
 | _optional_ | _optional_ | **`schema-id`**          | ID of the table's current schema when the snapshot was created |