docs: drop internal from manual

internal developer document don't have good description

Signed-off-by: Hiroshi Miura <miurahr@linux.com>

docs/index.rst

@@ -10,7 +10,6 @@ Contents:
    cli
    available_versions
    configuration
-   internals
    changes
    devguide
    authors

docs/internals.rst

@@ -1,40 +0,0 @@
-:tocdepth: 2
-
-.. _internals:
-
-Internals
-=========
-
-.. _archives-objects:
-
-Installer module
-----------------
-
-.. automodule:: aqt.installer
-    :members:
-    :inherited-members:
-    :show-inheritance:
-
-
-Archives module
----------------
-
-.. automodule:: aqt.archives
-    :members:
-    :inherited-members:
-    :show-inheritance:
-
-
-Updater module
---------------
-
-.. automodule:: aqt.updater
-    :members:
-
-
-Helper module
--------------
-
-.. automodule:: aqt.helper
-    :members:
-