fix(commits_stats): add the expected attachment file

subjects/commits_stats/README.md

@@ -2,7 +2,7 @@
 
 ### Instructions:
 
-In this exercise, you will be provided with a json file `commits.json` with data corresponding to git commits in GitHub (extracted using the GitHub rest API). Your objective is to extract the relevant data and place it in a struct called `CommitData`.
+In this exercise, you will be provided with a json file `commits.json`([download](./attachments/commits.json)) with data corresponding to git commits in GitHub (extracted using the GitHub rest API). Your objective is to extract the relevant data and place it in a struct called `CommitData`.
 
 Create two functions:
 - `commits_per_author`: which returns a hash map with the number of commits per author. The auditors will be identified by their GitHub login.