docs/ustruct: There's no complete "struct" module, only "ustruct" subset.

"ustruct" is good example of micro-ified module, so rather should belong
to the corresponding list.

docs/library/index.rst

@@ -26,7 +26,6 @@ For additional libraries, please download them from the `micropython-lib reposit
        gc.rst
        math.rst
        os.rst
-       struct.rst
        sys.rst
        time.rst
 
@@ -40,7 +39,6 @@ For additional libraries, please download them from the `micropython-lib reposit
        math.rst
        os.rst
        select.rst
-       struct.rst
        sys.rst
        time.rst
 
@@ -62,7 +60,6 @@ For additional libraries, please download them from the `micropython-lib reposit
 
        gc.rst
        math.rst
-       struct.rst
        sys.rst
        time.rst
 
@@ -94,6 +91,7 @@ library.
       ujson.rst
       ure.rst
       usocket.rst
+      ustruct.rst
       uzlib.rst
 
 .. only:: port_esp8266
@@ -107,6 +105,7 @@ library.
       uheapq.rst
       ujson.rst
       ure.rst
+      ustruct.rst
       uzlib.rst
 
 .. only:: port_pyboard

docs/library/struct.rst → docs/library/ustruct.rst

@@ -1,7 +1,7 @@
-:mod:`struct` -- pack and unpack primitive data types
-=====================================================
+:mod:`ustruct` -- pack and unpack primitive data types
+======================================================
 
-.. module:: struct
+.. module:: ustruct
    :synopsis: pack and unpack primitive data types
 
 See `Python struct <https://docs.python.org/3/library/struct.html>`_ for more