Update getting_started doc for STRIP_LEADING_DIRECTORY_PATH var.

docs/getting_started.md

@@ -40,7 +40,7 @@ running as a Container or as a Systemd service.
 | `HEADER_PREFIXES_TO_STRIP`            | No        |                              |           | A list of HTTP header prefixes that exclude headers client responses. List should be specified in lower-case and a semicolon (;) should be used to as a deliminator between values. For example: `x-goog-;x-something-`                                                                                                                                                                                                                                      |
 | `CORS_ENABLED`                        | No        | `true`, `false`              | `false`   | Flag that enables CORS headers on GET requests and enables pre-flight OPTIONS requests. If enabled, this will add CORS headers for "fully open" cross domain requests by default, meaning all domains are allowed, similar to the settings show in [this example](https://enable-cors.org/server_nginx.html). CORS settings can be fine-tuned by overwriting the [`cors.conf.template`](/common/etc/nginx/templates/gateway/cors.conf.template) file.        |
 | `CORS_ALLOWED_ORIGIN`                 | No        |                              |           | value to set to be returned from the CORS `Access-Control-Allow-Origin` header. This value is only used if CORS is enabled. (default: \*)                                                                                                                                                                                                                                                 
-| `STRIP_LEADING_DIRECTORY_PATH`        | No        |                              |           | Removes a portion of the path in the requested URL (if configured). Useful when deploying to an ALB under a folder (eg. www.mysite.com/mybucket).
+| `STRIP_LEADING_DIRECTORY_PATH`        | No        |                              |           | Removes a portion of the path in the requested URL (if configured). Useful when deploying to an ALB under a folder (eg. www.mysite.com/somepath).
 
 If you are using [AWS instance profile credentials](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use_switch-role-ec2.html),
 you will need to omit the `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY` and `AWS_SESSION_TOKEN` variables from
@@ -104,6 +104,13 @@ It will also redirect `/some/path` to `/some/path/` when S3 returns 404 on
 look like a possible directory, it must not start with a `.` and not have an 
 extension.  
 
+### Hosting a Bucket as a Subfolder on an ALB
+
+The `STRIP_LEADING_DIRECTORY_PATH` environment variable allows one to host an
+S3 bucket in a subfolder on an ALB.  For example, if you wanted to expose the
+root of a bucket under the path "www.mysite.com/somepath", you would set this
+variable to "/somepath".
+
 ## Running as a Systemd Service
 
 An [install script](/standalone_ubuntu_oss_install.sh) for the gateway shows