fix: postinstall parm key

Author: Ehesp

extensions/image-processing-api/POSTINSTALL.md

@@ -29,7 +29,7 @@ encodeURIComponent(JSON.stringify(operations));
 
 3. Call the deployed `process` Cloud Function:
 
-[https://${PARAM:LOCATION}-${PARAM:PROJECT_ID}.cloudfunctions.net/ext-image-processing-api-handler/process?operations=%5B%7B%22operation%22%3A%22input%22%2C%22type%22%3A%22url%22%2C%22url%22%3A%22https%3A%2F%2Fimages.unsplash.com%2Fphoto-1663659552548-25d7771802c9%3Fixlib%3Drb-1.2.1%26ixid%3DMnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8%26auto%3Dformat%26fit%3Dcrop%26w%3D774%26q%3D80%22%7D%2C%7B%22operation%22%3A%22grayscale%22%7D%2C%7B%22operation%22%3A%22output%22%2C%22format%22%3A%22webp%22%7D%5D](https://${PARAM:LOCATION}-${PARAM:PROJECT_ID}.cloudfunctions.net/ext-image-processing-api-handler/process?operations=%5B%7B%22operation%22%3A%22input%22%2C%22type%22%3A%22url%22%2C%22url%22%3A%22https%3A%2F%2Fimages.unsplash.com%2Fphoto-1663659552548-25d7771802c9%3Fixlib%3Drb-1.2.1%26ixid%3DMnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8%26auto%3Dformat%26fit%3Dcrop%26w%3D774%26q%3D80%22%7D%2C%7B%22operation%22%3A%22grayscale%22%7D%2C%7B%22operation%22%3A%22output%22%2C%22format%22%3A%22webp%22%7D%5D)
+[https://${param:LOCATION}-${param:PROJECT_ID}.cloudfunctions.net/ext-image-processing-api-handler/process?operations=%5B%7B%22operation%22%3A%22input%22%2C%22type%22%3A%22url%22%2C%22url%22%3A%22https%3A%2F%2Fimages.unsplash.com%2Fphoto-1663659552548-25d7771802c9%3Fixlib%3Drb-1.2.1%26ixid%3DMnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8%26auto%3Dformat%26fit%3Dcrop%26w%3D774%26q%3D80%22%7D%2C%7B%22operation%22%3A%22grayscale%22%7D%2C%7B%22operation%22%3A%22output%22%2C%22format%22%3A%22webp%22%7D%5D](https://${param:LOCATION}-${param:PROJECT_ID}.cloudfunctions.net/ext-image-processing-api-handler/process?operations=%5B%7B%22operation%22%3A%22input%22%2C%22type%22%3A%22url%22%2C%22url%22%3A%22https%3A%2F%2Fimages.unsplash.com%2Fphoto-1663659552548-25d7771802c9%3Fixlib%3Drb-1.2.1%26ixid%3DMnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8%26auto%3Dformat%26fit%3Dcrop%26w%3D774%26q%3D80%22%7D%2C%7B%22operation%22%3A%22grayscale%22%7D%2C%7B%22operation%22%3A%22output%22%2C%22format%22%3A%22webp%22%7D%5D)
 
 The result will be a grayscaled version of the image, in WebP format.