Updated links on how_to_guides.rst files for the examples

[wzkariampuzha]

I checked most of them and didn't blindly convert .html -> .ipynb because some examples were html -> .rst

[wzkariampuzha]

Saw it failed the automatic link check, but that didn't check the *.rst files correctly. The changes work on my main branch.

[hwchase17]

i think the .html file extensions are actually need for this

is the only change in this pr changing away from .html extensions? because i think we actually WANT to keep that

[wzkariampuzha]

@hwchase17 I don't really care which extensions should be used for the examples linked in the how-to guides. I just see that most of the links are broken because the actual examples that they route to are *.ipynb files.

Example Click on the links in this guide on the main branch. It is supposed to redirect to the files in this folder which are all *.ipynb files, but currently the links are broken.

[wzkariampuzha]

But yes, otherwise the only change in this PR is changing .html extensions in hyperlinks to either .ipynb or .rst (depending on whichever was the correct file to route to).

[hwchase17]

ah got it - the links are built to work on the our documentation site, https://langchain.readthedocs.io/en/latest/modules/indexes/how_to_guides.html, and not github. there are benefits to having html (the link checker that is failing this test can only properly test if they are .html) so we probably wont fix

[wzkariampuzha]

Ah gotcha. Thank you for letting me know!