Update README.md

Co-authored-by: Lukasz Gornicki <[email protected]>

README.md

@@ -221,7 +221,7 @@ There is defined structure of adding the exrensions which is defined as followed
 1. All the extensions must be present in [./extensions](./extensions) folder.
 2. A proper folder structure must be followed to add the extensions.
 3. A new folder just as [x extension](./extensions/x) must be added with proper `versioning` and `schema file`.
-4. All the schemas must be added in a fle named `schema.json` just as one is defined for [x extension](./extensions/x/0.1.0/schema.json).
+4. All the schemas must be added in a file named `schema.json` just as one is defined for [x extension](./extensions/x/0.1.0/schema.json).
 
 5. Extension schema should not be referenced directly in the definition of the object it extends. For example if you add an extension for `info`, your extension's schema should not be referenced from `info.json` but [infoExtensions.json](./definitions/3.0.0/infoExtensions.json). If the object that you extend doesn't have a corresponding `*Extensions.json` file, you need to create one.