[Bug]: "Langchain.php file is not in correct location."

[pvillagram]

What happened?

When trying to use this port of Langchain for PHP I find that the main file Langchain.php is not located in the root of the namespace /src.

Only one version is present in /src/Exceptions, which causes errors when trying to load the class.

Please consider moving the file to the expected location in /src/Langchain.php so that the library can be used properly.

Also validate that the version in Exceptions is complete and correct for general use.

Thank you for your work on this unofficial port. It would be very useful to have a stable and well-implemented version of Langchain for PHP.

Best regards

How to reproduce the bug

1. Clone the Langchain repository for PHP:
   git clone https://github.com/kambo-1st/langchain-php

2. Install dependencies with Composer:
   composer install

3. Create an index.php file with the following code: