add sudo requirement for local install

[destan]

add sudo requirement for local install in the README

Description

It fails with following error if ./algo is not run with sudo:

fatal: [localhost]: FAILED! => {"changed": false, "msg": "non-zero return code", "rc": 1, "stderr": "sudo: a password is required\n", "stderr_lines": ["sudo: a password is required"], "stdout": "", "stdout_lines": []}

This happens when the algo script is run on the target machine.

I assume this would still happen if algo script run from another machine but the ssh user has no sudo privilege or requires a password for sudo. However, I didn't test this case hence didn't add anything about that.

Motivation and Context

How Has This Been Tested?

Tested with Ubuntu 20.04 updated today (2021-03-15) and algo repository with commit id 70f9f91.

Types of changes

• Readme update

Checklist:

• [x] I have read the CONTRIBUTING document.
• [] My code follows the code style of this project.
• [] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [] I have added tests to cover my changes.
• [] All new and existing tests passed.

[CLAassistant]

All committers have signed the CLA.