Try and properly support having config.d.ts away from the root folder

Signed-off-by: Karan Shah <karan.shah@simplybusiness.co.uk>

plugins/airbrake-backend/package.json

@@ -39,8 +39,9 @@
   },
   "files": [
     "dist",
-    "config.d.ts"
+    "src/config/config.d.ts"
   ],
+  "configSchema": "src/config/config.d.ts",
   "jest": {
     "coverageThreshold": {
       "global": {

plugins/airbrake-backend/src/config/index.ts

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import { Config } from '../../config';
+import { Config } from './config';
 
 export { extractAirbrakeConfig } from './ExtractAirbrakeConfig';
 export type AirbrakeConfig = Config['airbrake'];