docs: update storage guide

Author: AsifArmanRahman

docs/guide/storage.rst

@@ -4,6 +4,13 @@ Storage
 The storage service allows you to upload files (eg. text, image,
 video) to Firebase.
 
+.. code-block:: python
+
+   # Create storage instance
+   storage = firebaseApp.storage()
+..
+
+
 child
 -----
 
@@ -13,6 +20,10 @@ with the Storage service.
 .. code-block:: python
 
    storage.child("images/example.jpg")
+
+   # Alternative ways
+   storage.child("images").child("example.jpg")
+   storage.child("images", "example.jpg")
 ..
 
 put
@@ -23,9 +34,9 @@ token.
 
 .. code-block:: python
 
-   storage = firebaseApp.storage()
    # as admin
    storage.child("images/example.jpg").put("example2.jpg")
+
    # as user
    storage.child("images/example.jpg").put("example2.jpg", user['idToken'])
 ..
@@ -38,7 +49,11 @@ name you want the downloaded file to have.
 
 .. code-block:: python
 
+  # as admin
    storage.child("images/example.jpg").download("downloaded.jpg")
+
+   # as user
+   storage.child("images/example.jpg").download("downloaded.jpg", user['idToken'])
 ..
 
 get_url
@@ -49,8 +64,17 @@ token which returns the storage url.
 
 .. code-block:: python
 
+   # as admin
+   storage.child("images/example.jpg").get_url()
+
+   # as admin with expiration time for link to expire
+   storage.child("images/example.jpg").get_url(expiration_hour=12)
+
+   # as user
    storage.child("images/example.jpg").get_url(user["idToken"])
-   # https://firebasestorage.googleapis.com/v0/b/storage-url.appspot.com/o/images%2Fexample.jpg?alt=media
+
+   # returned URL example:
+   # https://firebasestorage.googleapis.com/v0/b/storage-url.appspot.com/o/images%2Fexample.jpg?alt=media&token=$token
 ..
 
 delete
@@ -61,5 +85,20 @@ token.
 
 .. code-block:: python
 
-   storage.delete("images/example.jpg",user["idToken"])
+   # as admin
+   storage.child("images/example.jpg").delete()
+
+   # as user
+   storage.child("images/example.jpg").delete(user["idToken"])
+..
+
+list_of_files
+-------------
+
+The list_of_files method works only if used under admin credentials.
+
+.. code-block:: python
+
+   # as admin
+   storage.list_of_files()
 ..