Change descriptions to use push function

Author: sebromero

Diff for: docs/02-data-exchange.md

@@ -16,7 +16,7 @@ SHARED(counter, int); /* A globally available, threadsafe, shared variable of ty
 SHARED(counter, int, 8); /* Same as before, but now the internal queue size is defined as 8. */
 ```
 Writing to and reading from the shared variable may not always happen concurrently. I.e. a thread reading sensor data may update the shared variable faster than a slower reader thread would extract those values. Therefore the shared variable is modeled as a queue which can store (buffer) a certain number of entries. That way the slower reader thread can access all the values in the same order as they have been written.
-New values can be inserted naturally by using the assignment operator `=` as if it was just any ordinary variable type, i.e. `int`, `char`, ...
+New values can be inserted by using the `push` function that you may know from other data structures.
 
 ```C++
 /* Thread_1.inot */