Rename the recently changed how guides in index.rst (toctree)

[adam-narozniak]

Problem:
There are two recently renamed how-to guides missing from the website.
Explanation:
The newly changed names of how-to guides (names of files in docs/source/*.rst) were changed but left the same in index.rst in the toctree structure.
Solution:
The names in the index.rst were changed to reflect the names in the docs/source/*.rst.

[danieljanes]

Lgtm, thanks for the fix!