docs: fix typo in the README.md (#459)

Author: b-zurg

README.md

@@ -161,7 +161,7 @@ Options for the TypeScript checker (`typescript` option object).
 | `configOverwrite`    | `object`  | `{ compilerOptions: { skipLibCheck: true, sourceMap: false, inlineSourceMap: false, declarationMap: false } }` | This configuration will overwrite configuration from the `tsconfig.json` file. Supported fields are: `extends`, `compilerOptions`, `include`, `exclude`, `files`, and `references`. |
 | `context`            | `string`  | `dirname(configuration.configFile)`                                                                            | The base path for finding files specified in the `tsconfig.json`. Same as the `context` option from the [ts-loader](https://github.com/TypeStrong/ts-loader#context). Useful if you want to keep your `tsconfig.json` in an external package. Keep in mind that **not** having a `tsconfig.json` in your project root can cause different behaviour between `fork-ts-checker-webpack-plugin` and `tsc`. When using editors like `VS Code` it is advised to add a `tsconfig.json` file to the root of the project and extend the config file referenced in option `configFile`.  |
 | `build`              | `boolean` | `false`                                                                                                        | The equivalent of the `--build` flag for the `tsc` command. |
-| `mode`               | `'readonly'` or `'write-tsbuildinfo'` or `'write-references'` | `'write-tsbuildinfo'`                                      | If you use the `babel-loader`, it's recommended to use `write-references` mode to improve initial compilation time. If you use `ts-loader`, it's recommended to use `write-tsbuildinfo` mode to not overwrite filed emitted by the `ts-loader`. |
+| `mode`               | `'readonly'` or `'write-tsbuildinfo'` or `'write-references'` | `'write-tsbuildinfo'`                                      | If you use the `babel-loader`, it's recommended to use `write-references` mode to improve initial compilation time. If you use `ts-loader`, it's recommended to use `write-tsbuildinfo` mode to not overwrite files emitted by the `ts-loader`. |
 | `diagnosticOptions` | `object`  | `{ syntactic: false, semantic: true, declaration: false, global: false }`                                      | Settings to select which diagnostics do we want to perform. |
 | `extensions`         | `object`  | `{}`                                                                                                           | See [TypeScript extensions options](#typescript-extensions-options). |
 | `profile`            | `boolean` | `false`                                                                                                        | Measures and prints timings related to the TypeScript performance. |