rename repo namespace to langchain-ai (#11259)

### 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)

.github/CONTRIBUTING.md

@@ -32,7 +32,7 @@ best way to get our attention.
 
 ### 🚩GitHub Issues
 
-Our [issues](https://github.com/hwchase17/langchain/issues) page is kept up to date
+Our [issues](https://github.com/langchain-ai/langchain/issues) page is kept up to date
 with bugs, improvements, and feature requests.
 
 There is a taxonomy of labels to help with sorting and discovery of issues of interest. Please use these to help
@@ -60,7 +60,7 @@ we do not want these to get in the way of getting good code into the codebase.
 ## 🚀 Quick Start
 
 This quick start describes running the repository locally.
-For a [development container](https://containers.dev/), see the [.devcontainer folder](https://github.com/hwchase17/langchain/tree/master/.devcontainer).
+For a [development container](https://containers.dev/), see the [.devcontainer folder](https://github.com/langchain-ai/langchain/tree/master/.devcontainer).
 
 ### Dependency Management: Poetry and other env/dependency managers
 

.github/ISSUE_TEMPLATE/feature-request.yml

@@ -27,4 +27,4 @@ body:
     attributes:
       label: Your contribution
       description: |
-        Is there any way that you could help, e.g. by submitting a PR? Make sure to read the CONTRIBUTING.MD [readme](https://github.com/hwchase17/langchain/blob/master/.github/CONTRIBUTING.md)
+        Is there any way that you could help, e.g. by submitting a PR? Make sure to read the CONTRIBUTING.MD [readme](https://github.com/langchain-ai/langchain/blob/master/.github/CONTRIBUTING.md)

.github/PULL_REQUEST_TEMPLATE.md

@@ -10,7 +10,7 @@ Replace this entire comment with:
 Please make sure your PR is passing linting and testing before submitting. Run `make format`, `make lint` and `make test` to check this locally.
 
 See contribution guidelines for more information on how to write/run tests, lint, etc: 
-https://github.com/hwchase17/langchain/blob/master/.github/CONTRIBUTING.md
+https://github.com/langchain-ai/langchain/blob/master/.github/CONTRIBUTING.md
 
 If you're adding a new integration, please include:
   1. a test for the integration, preferably unit tests that do not rely on network access,