Make hyperlinks to sub-tasks compact (#50)

diff --git a/migration/src/jira2github_import.py b/migration/src/jira2github_import.py
index db6da81..88d101b 100644
--- a/migration/src/jira2github_import.py
+++ b/migration/src/jira2github_import.py
@@ -76,7 +76,7 @@
         # embed github issue number next to sub task keys
         subtasks_list_items = []
         for jira_key in subtasks:
-            subtasks_list_items.append(f"{jira_key} : [Jira link]({jira_issue_url(jira_key)})")
+            subtasks_list_items.append(f"[{jira_key}]({jira_issue_url(jira_key)})")
 
         created_datetime = dateutil.parser.parse(created)
         updated_datetime = dateutil.parser.parse(updated)