DOC: Add missing attributes and methods to MultiIndex API documentation (#50594)

* Add attributes and methods to MultiIndex documentation page to make it self contained

* move IndexSlice away from MultiIndex

* split IndexSlice as new category

* move IndexSlice to multiIndex
as It's under multiIndex category

Co-authored-by: Elvis Lim <[email protected]>

Author: Elvislim1991

doc/source/reference/indexing.rst

@@ -253,14 +253,14 @@ MultiIndex
 ----------
 .. autosummary::
    :toctree: api/
-   :template: autosummary/class_without_autosummary.rst
 
-   MultiIndex
+   IndexSlice
 
 .. autosummary::
    :toctree: api/
+   :template: autosummary/class_without_autosummary.rst
 
-   IndexSlice
+   MultiIndex
 
 MultiIndex constructors
 ~~~~~~~~~~~~~~~~~~~~~~~

pandas/core/indexes/multi.py

@@ -239,6 +239,7 @@ class MultiIndex(Index):
     codes
     nlevels
     levshape
+    dtypes
 
     Methods
     -------
@@ -255,7 +256,12 @@ class MultiIndex(Index):
     swaplevel
     reorder_levels
     remove_unused_levels
+    get_level_values
+    get_indexer
+    get_loc
     get_locs
+    get_loc_level
+    drop
 
     See Also
     --------