SnowEx/snowexsql: snowexsql-v1.1.0

New Features Lambda Function URL support (PR #209): The SnowExLambdaClient now supports HTTP POST-based invocations via an AWS Lambda Function URL, enabling public access without AWS credentials. The lambda_handler was also updated to handle these HTTP requests, and the test script (test_lambda.sh) was extended to cover Function URL scenarios. Documentation overhaul (closes #153): Major rewrite of the README, usage.rst, api.rst, and database_structure.rst for clarity and accuracy. Adds Mermaid diagrams as a docs dependency for improved schema visualization. Bug Fixes Pinned version ranges for requests and urllib3 dependencies to improve install reliability. Improved error messages in the Lambda client and handler. Clarified Lambda Client docstring to accurately describe credential requirements. Housekeeping Removed outdated documentation content. Minor formatting and readability improvements across the codebase. Added DOI to README and fixed prose grammar.