docs: re-init an env var in the third terminal (#128)
docs: re-init an env var in the third terminal (#128)

- To make sure that the commands can be run if copied and pasted, need to reinitialize an environment variable in the third terminal. 

- Add command to install `google-cloud-python`

Confirmed that it works when copied and pasted! 
GoogleCloudPlatform/functions-framework-python,GoogleCloudPlatform/functions-framework-python,GoogleCloudPlatform/functions-framework-python