DOC: Fix typos found by codespell

Changelog

@@ -1246,7 +1246,7 @@ Special thanks to Chris Burns, Jarrod Millman and Yaroslav Halchenko.
 * Very preliminary, limited and highly experimental DICOM reading support (MB,
   Ian Nimmo Smith).
 * Some functions (:py:mod:`nibabel.funcs`) for basic image shape changes, including
-  the ability to transform to the image with data closest to the cononical
+  the ability to transform to the image with data closest to the canonical
   image orientation (first axis left-to-right, second back-to-front, third
   down-to-up) (MB, Jonathan Taylor)
 * Gifti format read and write support (preliminary) (Stephen Gerhard)

doc/source/devel/biaps/biap_0006.rst

@@ -202,7 +202,7 @@ here is the definition of a "multi-frame image"::
     3.8.9 Multi-frame image:
         Image that contains multiple two-dimensional pixel planes.
 
-From `PS 3.3 of the 2011 DICOM standrd
+From `PS 3.3 of the 2011 DICOM standard
 <http://medical.nema.org/Dicom/2011/11_03pu.pdf>`_.
 
 **********************************

nibabel/pointset.py

@@ -126,7 +126,7 @@ def get_coords(self, *, as_homogeneous: bool = False):
         ----------
         as_homogeneous : :class:`bool`
             Return homogeneous coordinates if ``True``, or Cartesian
-            coordiantes if ``False``.
+            coordinates if ``False``.
 
         name : :class:`str`
             Select a particular coordinate system if more than one may exist.