Fix typo in error message formatting in repository.ts and FAQ section of README

Author: andrey-helldar

README.md

@@ -174,7 +174,7 @@ Ultimately, the image link will look like this:
 
 ## FAQ
 
-> 💥 Preview Updater failed with error: Error when creating pull request from preview/banner-***: GitHub Actions is not permitted to create or approve pull requests
+> 💥 Preview Updater failed with error: Error when creating a pull request from preview/banner-***: GitHub Actions is not permitted to create or approve pull requests
 
 Enable the "Allow GitHub Actions to create and approve pull requests" option in project settings.
 

src/utils/repository.ts

@@ -152,7 +152,7 @@ export class Repository {
             });
         } catch (error) {
             // @ts-expect-error
-            error.message = `Error when creating pull request from ${this.branchName()}: ${error.message}`;
+            error.message = `Error when creating a pull request from ${this.branchName()}: ${error.message}`;
 
             throw error;
         }