Unify "byte code" to "bytecode". Also sprinkle :term: markup for it.
diff --git a/Doc/documenting/markup.rst b/Doc/documenting/markup.rst
index 690d056..a246d62 100644
--- a/Doc/documenting/markup.rst
+++ b/Doc/documenting/markup.rst
@@ -210,7 +210,7 @@
 
 .. describe:: opcode
 
-   Describes a Python bytecode instruction.
+   Describes a Python :term:`bytecode` instruction.
 
 .. describe:: cmdoption