Added loader to Download Image + modified GitHub stars (#5407)

- Added loader to download image in contributor page:


https://github.com/twentyhq/twenty/assets/102751374/a6db1d80-01ed-4b07-9a57-e533012f5aa9

- Modified GitHub stars - rounded to the nearest integer

packages/twenty-website/src/shared-utils/formatNumberOfStars.ts

@@ -1,3 +1,3 @@
 export const formatNumberOfStars = (numberOfStars: number) => {
-  return Math.ceil(numberOfStars / 100) / 10 + 'k';
+  return Math.round(numberOfStars / 100) / 10 + 'k';
 };