### Description
When I was reading the document, I found that some examples had extra
spaces and violated "Unexpected spaces around keyword / parameter equals
(E251)" in pep8. I removed these extra spaces.
### Tag maintainer
@eyurtsev
### Twitter handle
[billvsme](https://twitter.com/billvsme)
### Description
renamed several repository links from `hwchase17` to `langchain-ai`.
### Why
I discovered that the README file in the devcontainer contains an old
repository name, so I took the opportunity to rename the old repository
name in all files within the repository, excluding those that do not
require changes.
### Dependencies
none
### Tag maintainer
@baskaryan
### Twitter handle
[kzk_maeda](https://twitter.com/kzk_maeda)
