Add migration guide link (#327)

Author: thomasrockhu-codecov

README.md

@@ -2,7 +2,7 @@
 
 This uploader is being deprecated by the Codecov team. We recommend migrating to our [new uploader](https://docs.codecov.com/docs/codecov-uploader) as soon as possible to prevent any lapses in coverage. [The new uploader is open source](https://github.com/codecov/uploader), and we highly encourage submitting Issues and Pull Requests.
 
-You can visit our blog post to learn more about our [deprecation plan](https://about.codecov.io/blog/codecov-uploader-deprecation-plan/)
+You can visit our [migration guide](https://docs.codecov.com/docs/deprecated-uploader-migration-guide#python-uploader) for help moving to our new uploader, and our blog post to learn more about our [deprecation plan](https://about.codecov.io/blog/codecov-uploader-deprecation-plan/)
 
 **On February 1, 2022 this uploader will be completely deprecated and will no longer be able to upload coverage to Codecov.**