update README links to tagged releases on pypi and npm

Links that point to samples, etc in the repo that are found on PyPi and npm pages are not updated to the tagged release links.

Examples (click on "Samples" for either page and they go to main):

https://pypi.org/project/azure-ai-textanalytics/
https://www.npmjs.com/package/@azure/ai-text-analytics

If we can update these links to the tagged release versions this would be helpful for customers. We already do this for github.io and MS docs so hopefully that solution can just be applied here?