added composer files and installed vendor packages. Also modified xsls to display base project

vendor/maennchen/zipstream-php/guides/PSR7Streams.rst

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+Usage with PSR 7 Streams
+===============
+
+PSR-7 streams are `standardized streams <https://www.php-fig.org/psr/psr-7/>`_.
+
+ZipStream-PHP supports working with these streams with the function
+``addFileFromPsr7Stream``. 
+
+For all parameters of the function see the API documentation.
+
+Example
+---------------
+
+.. code-block:: php
+
+    $stream = $response->getBody();
+    // add a file named 'streamfile.txt' from the content of the stream
+    $zip->addFileFromPsr7Stream(
+        fileName: 'streamfile.txt',
+        stream: $stream,
+    );