docs: Update supported go versions in readme

[JohnRoesler]

Fixes

The minimum go version set by the Go mod file is 1.16. Because of Go's compatibility promise there is no need to list out all the Go version beyond the minimum support version as anything 1.16+ supports this library.

Thanks for the Go implementation!

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the Contribution Guidelines and my PR follows them
• I have titled the PR appropriately
• I have updated my branch with the main branch
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

If you have questions, please file a support ticket, or create a GitHub Issue in this repository.