Update README.md

Author: ankostenko

README.md

@@ -6,7 +6,8 @@
   - cd 
   - program execution
   - path resolution
-  - I/O redirection
+  - I/O redirection (There is the comment in the code about pipes, 
+          so turned out that pipes are being created in other way than I thought, but the comment is still right)
   - Signal handling (very limited)
     - We can't kill processes 
     - Processes that works in the background still running even after work of the shell is done