Add access/secret key config parameters

Author: danmooney2

docs/configuration.md

@@ -408,6 +408,26 @@ Example:
 REMOTE_STORAGE_AWSS3_PREFIX=local
 ```
 
+### REMOTE_STORAGE_AWSS3_ACCESS_KEY
+
+The optional access key for the S3 bucket.
+
+Example:
+
+```conf
+REMOTE_STORAGE_AWSS3_ACCESS_KEY=access-key
+```
+
+### REMOTE_STORAGE_AWSS3_SECRET_KEY
+
+The optional secret key for the S3 bucket.
+
+Example:
+
+```conf
+REMOTE_STORAGE_AWSS3_SECRET_KEY=secret-key
+```
+
 ### MAGENTO_ADMIN_WEBAPI_TOKEN_LIFETIME
 
 The lifetime (in seconds) of Magento Admin WebAPI token; if token is older than this value a refresh attempt will be made just before the next WebAPI call.