docs: Adapt shell completion subsection (#3672)

Signed-off-by: Julien Jerphanion <[email protected]>

docs/source/installation/micromamba-installation.rst

@@ -230,30 +230,3 @@ The executable can be striped to remove its size:
 .. code:: bash
 
    strip "build/micromamba/micromamba"
-
-
-.. _shell_completion:
-
-Shell completion
-****************
-
-For now, only ``micromamba`` provides shell completion on ``bash`` and ``zsh``.
-
-To activate it, it's as simple as running:
-
-.. code:: bash
-
-  micromamba shell completion
-
-The completion is now available in any new shell opened or in the current shell after sourcing the configuration file to take modifications into account.
-
-.. code-block:: sh
-
-  source ~/.<shell>rc
-
-| Just hit ``<TAB><TAB>`` to get completion when typing your command.
-| For example the following command will help you to pick a named environment to activate:
-
-.. code-block:: bash
-
-  micromamba activate <TAB><TAB>

docs/source/user_guide/concepts.rst

@@ -85,3 +85,18 @@ Deactivation
 ************
 
 The *deactivation* is the opposite operation of :ref:`activation<activation>`, removing from your shell what makes the environment content accessible.
+
+
+.. _shell_completion:
+
+Shell completion
+****************
+
+After initialization, shell completion is available in any new shell.
+Just hit ``<TAB><TAB>`` to get completion when typing your command.
+
+For example the following command will help you to pick a named environment to activate:
+
+.. code-block:: bash
+
+  micromamba activate <TAB><TAB>