Add a command to setup virtualenv in the Readme file.

[valaparthvi]

I would like to request a change in the Readme file.
I'm submitting a ...

• bug report
• feature request

Description: Correct me if I'm wrong, but I think setting up a virtualenv is mandatory before running the search engine locally. Curently, there is no mention of creating a virtual environment in the Readme instructions. Even though it's quite obvious, I think mentioning it in the instructions will be helpful to new contributors.

Would you like to work on this issue?

• Yes
• No