Regenerate the README files and fix the Open in Cloud Shell link for some samples [(#1441)](GoogleCloudPlatform/python-docs-samples#1441)

Author: chenyumic

samples/README.rst

@@ -59,7 +59,7 @@ Quickstart
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 .. image:: https://gstatic.com/cloudssh/images/open-btn.png
-   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/quickstart.py;/README.rst
+   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/quickstart.py,/README.rst
 
 
 
@@ -75,7 +75,7 @@ List voices
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 .. image:: https://gstatic.com/cloudssh/images/open-btn.png
-   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/list_voices.py;/README.rst
+   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/list_voices.py,/README.rst
 
 
 
@@ -91,7 +91,7 @@ Synthesize text
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 .. image:: https://gstatic.com/cloudssh/images/open-btn.png
-   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/synthesize_text.py;/README.rst
+   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/synthesize_text.py,/README.rst
 
 
 
@@ -121,7 +121,7 @@ Synthesize file
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 .. image:: https://gstatic.com/cloudssh/images/open-btn.png
-   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/synthesize_file.py;/README.rst
+   :target: https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&page=editor&open_in_editor=/synthesize_file.py,/README.rst