docs: add v1 to v2 automated migration link + cli command (#930)

Co-authored-by: Aleksy Rybicki <[email protected]>

Author: covolute-release

docs/blog/v2.md

@@ -41,6 +41,14 @@ The only change in v2 is that Shiki will now **emit warnings when you use deprec
 
 Expect v3.0.0 to be released soon after v2.0.0.
 
+## Automated Migration
+
+To help with the migration process, community member [Covolute](https://covolute.com/registry/shiki/v1-to-v2) provides an automated codemod that handles most of the API changes from v1 to v2. You can run it directly with:
+
+```bash
+npx covolute@latest shiki/v1-to-v2
+```
+
 ## Deprecations
 
 We highly recommend you to migrate the depreactions as soon as possible, with the warning messages as a guide.