message: Fix warning message for __TS_CONFIG__ deprecation
diff: @@ -115,7 +115,8 @@ By default this package will try to locate `tsconfig.json` and use its compiler
  You can override this behaviour by pointing ts-jest to a custom TypeScript configuration file.
  You can do this by setting the `tsConfigFile` option in your global variables under the `ts-jest` key to path of the
  -custom configuration file (relative to the project's root directory) *__TS_CONFIG__ is deprecated*
  +custom configuration file (relative to the project's root directory)
  +
  ```json
  {
  "jest": {
  @@ -127,7 +128,7 @@ custom configuration file (relative to the project's root directory) *__TS_CONFI
  }
  }
  ```
  -**Warning: Using __TS_CONFIG__ option in globals is deprecated and soon will be removed.**
  +**Warning: Using \_\_TS_CONFIG__ option in globals is deprecated and soon will be removed.**
  For all available `tsc` options see [TypeScript docs](https://www.typescriptlang.org/docs/handbook/compiler-options.html).
  