refactor: group S3 config fields together

docs/configuration.md

@@ -104,12 +104,12 @@ The S3 backend has the following fields:
 - `endpoint`: The URL of the S3 endpoint to connect to
 - `bucket`: The name of the S3 bucket to use for storage. This bucket must already exist and your credentials must have access to it
 - `region`: The region where your S3 bucket is located
+- `path`: The base directory where all the media files will be stored (defaults to
+  root of the bucket)
 - `key`: Your Access Key ID
 - `secret`: Your Secret Access Key
 - `duration`:  The time (in seconds) that signed requests to the S3 bucket will be valid (default: `30`)
 - `bucket_use_path`: Controls the structure of the path to files in S3. If `true`, the bucket name will be included as part of the file path. If `false` (or omitted), it will be used as the bucket name in the domain name
-- `path`: The base directory where all the media files will be stored (defaults to
-  root of the bucket)
 - `directory_structure`: This is a table, used to configure how files are to be distributed within
   the media directory (see [Filesystem backend](#filesystem-backend) for details)
 

src/config/mod.rs

@@ -515,13 +515,15 @@ pub enum IncompleteMediaBackendConfig {
         endpoint: Url,
         bucket: String,
         region: String,
+        path: Option<String>,
+
         key: String,
         secret: String,
+
         #[serde(default = "default_s3_duration")]
         duration: u64,
         #[serde(default = "false_fn")]
         bucket_use_path: bool,
-        path: Option<String>,
         #[serde(default)]
         directory_structure: DirectoryStructure,
     },