Fix minor formatting and documentation inconsistencies in README

[amolak21]

This PR fixes minor inconsistencies and formatting issues in the README file.
Changes include:

• Fixed indentation and markdown issues.
• Updated C++ standard in the example (-std=c++11 → -std=c++14).
• Corrected list formatting.

No functional changes were made to the benchmark code.

[google-cla]

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[amolak21]

Hi, I've updated the documentation as per issue #1943. Could someone please review it when available?

[amolak21]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

I have signed the CLA

[LebedevRI]

I don't see the change the PR subject is talking about.

[amolak21]

I have updated the PR title and description to better reflect the changes.
Please review when you get a chance.

[LebedevRI]

CLA check still seems to be having issues.

[dmah42]

forced a rescan

[LebedevRI]

Not that i care either way, but i'm a bit confused by the rest of the changes here -- both the old and the new variants are equivalent as far as MarkDown is concerned, no?