chore(developer): update sidebar min width CSS variable documentation

Signed-off-by: Grigory Vodyanov <scratchx@gmx.com>

Author: GVodyanov

developer_manual/html_css_design/css.rst

@@ -228,7 +228,7 @@ Element structure variables
 +----------------------------------------------+------------------------------------------------+-----------------------------------------------------------------------------------------------------------+
 | ``--navigation-width``                       | ``300px``                                      | Width of the in-app navigation sidebar                                                                    |
 +----------------------------------------------+------------------------------------------------+-----------------------------------------------------------------------------------------------------------+
-| ``--sidebar-min-width``                      | ``200px``                                      | Minimum width of the app sidebar on small screens                                                         |
+| ``--sidebar-min-width``                      | ``300px``                                      | Minimum width of the app sidebar on small screens                                                         |
 +----------------------------------------------+------------------------------------------------+-----------------------------------------------------------------------------------------------------------+
 | ``--sidebar-max-width``                      | ``500px``                                      | Maximum width of the app sidebar on wide screens                                                          |
 +----------------------------------------------+------------------------------------------------+-----------------------------------------------------------------------------------------------------------+