Backport PR #13652: Fix typo in `shell_mimerenderer.rst`

docs/source/config/shell_mimerenderer.rst

@@ -1,60 +1,60 b''
 
 .. _shell_mimerenderer:
 
 
 Mime Renderer Extensions
 ========================
 
 Like it's cousins, Jupyter Notebooks and JupyterLab, Terminal IPython can be
 thought to render a number of mimetypes in the shell. This can be used to either
 display inline images if your terminal emulator supports it; or open some
 display results with external file viewers.
 
-Registering new mimetype handlers can so far only be done my extensions and
+Registering new mimetype handlers can so far only be done by extensions and
 requires 4 steps:
 
    - Define a callable that takes 2 parameters:``data`` and ``metadata``; return
      value of the callable is so far ignored. This callable is responsible for
      "displaying" the given mimetype. Which can be sending the right escape
      sequences and bytes to the current terminal; or open an external program. -
    - Appending the right mimetype to ``ipython.display_formatter.active_types``
      for IPython to know it should not ignore those mimetypes.
    - Enabling the given mimetype: ``ipython.display_formatter.formatters[mime].enabled = True``
    - Registering above callable with mimetype handler:
      ``ipython.mime_renderers[mime] = handler``
 
 
 Here is a complete IPython extension to display images inline and convert math
 to png, before displaying it inline for iterm2 on macOS ::
 
 
     from base64 import encodebytes
     from IPython.lib.latextools import latex_to_png
 
 
     def mathcat(data, meta):
         png = latex_to_png(f'$${data}$$'.replace('\displaystyle', '').replace('$$$', '$$'))
         imcat(png, meta)
 
     IMAGE_CODE = '\033]1337;File=name=name;inline=true;:{}\a'
 
     def imcat(image_data, metadata):
         try:
             print(IMAGE_CODE.format(encodebytes(image_data).decode()))
         # bug workaround
         except:
             print(IMAGE_CODE.format(image_data))
 
     def register_mimerenderer(ipython, mime, handler):
         ipython.display_formatter.active_types.append(mime)
         ipython.display_formatter.formatters[mime].enabled = True
         ipython.mime_renderers[mime] = handler
 
     def load_ipython_extension(ipython):
         register_mimerenderer(ipython, 'image/png', imcat)
         register_mimerenderer(ipython, 'image/jpeg', imcat)
         register_mimerenderer(ipython, 'text/latex', mathcat)
 
 This example only work for iterm2 on macOS and skip error handling for brevity.
 One could also invoke an external viewer with ``subprocess.run()`` and a
 temporary file, which is left as an exercise.