Update the readme for clarity on installing releases

[capraMambrica]

Is your feature request related to a problem? Please describe.
A an artist who is an absolute beginner to GitHub, I would like clear steps to "Install" the "Releases", so that I can take advantage of USD in my workflows.

Describe the solution you'd like
A simple line or two added to the Readme would suffice:

Installation
Download the and install the latest release for your platform here!

Describe alternatives you've considered
I spent considerable time fumbling around, trying to build the code myself, but actually got blocked building openUSD on a silicon, which I feel blocked me from installing mayaUSD. When eventually learned that there releases available to me, I felt kinda silly.

Additional context
As USD matures, we'll be seeing more artists wanting to update their Maya plugin the latest, and most will not event attempt to build. We should reduce all friction when getting the latest releases in their hands, so we'll get more hands on the tools.

[santosg87]

thank you for the recommendation! it definitely doesn't hurt to have helpful links with more visibility. I can update our documentation to reflect that. :)

[santosg87]

#3524 should take care of this. :)