Recommend @ts-expect-error over @ts-ignore (#489)

Co-authored-by: eps1lon <silbermann.sebastian@gmail.com>

Author: capaj

docs/migration/index.md

@@ -28,7 +28,7 @@ Read [TypeScript's official Guide for migrating from JS](https://www.typescriptl
 
 Misc tips/approaches successful companies have taken
 
-- `@ts-ignore` on compiler errors for libraries with no typedefs
+- `@ts-expect-error` on compiler errors for libraries with no typedefs
 - pick ESLint over TSLint (source: [ESLint](https://eslint.org/blog/2019/01/future-typescript-eslint) and [TS Roadmap](https://github.com/Microsoft/TypeScript/issues/29288)). [You can convert TSlint to ESlint with this tool](https://github.com/typescript-eslint/tslint-to-eslint-config).
 - New code must always be written in TypeScript. No exceptions. For existing code: If your task requires you to change JavaScript code, you need to rewrite it. (Source: [Hootsuite][hootsuite])