Fixed naming convention + added conclusion because I feel it ends abruptly

Author: mahmoud-moursy

doc/contributing/investigating_native_memory_leak.md renamed to doc/contributing/investigating-native-memory-leak.md

@@ -450,3 +450,6 @@ Running Valgrind using the debug build of Node.js shows:
 
 Now we can see the specific file name and line in the Node.js code which
 caused the allocation (inspector\_agent.cc:140).
+
+Thusly, we can examine the line (and its surrounding code) in order
+to find a potential solution for the memory leak.