update ambiguous <OPTIONS> language in README to incl. mandatory USD installation path

[michaelybecker]

…path parameter

(nonspecific error when it's not included, referenced in #5)

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

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

[michaelybecker]

Just a quick docs update seeing as the omission has tripped people before me

[michaelybecker]

I signed the CLA shortly before filing - perhaps some process or cache hasn't updated?

[kwblackstone]

looks good, thanks!