Fix #1492, Correct README.md OSAL User's Guide links

[leighgarbs]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution
Fixes #1492

Testing performed
Steps taken to test the contribution:

1. Follow the modified README.md links at https://github.com/leighgarbs/osal/blob/fix-1492-correct-readme-osal-users-guide-links/README.md

Expected behavior changes
The README.md links to the OSAL User's Guide link to the OSAL User's Guide.

System(s) tested on

• macOS laptop in Chrome browser

Contributor Info - All information REQUIRED for consideration of pull request
Leigh Garbs, NASA

[leighgarbs]

I could contribute as an individual and sign the Individual CLA, but I'm a NASA employee and would like to contribute as a NASA employee. Do NASA employees have to sign a CLA?

[dzbaker]

I could contribute as an individual and sign the Individual CLA, but I'm a NASA employee and would like to contribute as a NASA employee. Do NASA employees have to sign a CLA?

Hi @leighgarbs, thanks for your contribution! NASA employees do not need to sign a CLA.