docs/library/sys.rst: Add note about .frozen.

jimmo · jimmo · commit ad63c59d8ff5 · 2021-12-11T23:39:40.000+11:00
Signed-off-by: Jim Mussared &lt;jim.mussared@gmail.com&gt;
diff --git a/docs/library/sys.rst b/docs/library/sys.rst
@@ -115,6 +115,11 @@ Constants
 
    A mutable list of directories to search for imported modules.
 
+   .. admonition:: Difference to CPython
+      :class: attention
+
+      On MicroPython, an entry with the value ``".frozen"`` will indicate that it should search :term:`frozen modules`.
+
 .. data:: platform
 
    The platform that MicroPython is running on. For OS/RTOS ports, this is
