general/drills: Add "Distributed system" written task as exam

Refactor distributed-system.md

Signed-off-by: Petru-Vlad Ionescu <[email protected]>

chapters/general/drills/tasks/distributed-system.md

@@ -5,7 +5,7 @@
 We are designing a distributed e-learning system across multiple servers.
 The system consists of frontend services to handle client requests (for example, when a client accesses https://curs.upb.ro) and backend services for information storage.
 
-Respond to the following questions with "True" or "False" and provide reasoning for each answer. 
+Respond to the following questions with "True" or "False" and provide reasoning for each answer.
 The explanation should be concise, 2-3 sentences for each response.
 
 ## Questions