Update documentation script

[bybatkhuu]

This pull request updates the documentation script (docs.sh) to include options for serving a local documentation server or building the documentation as static HTML files. The script now includes the base.sh script to gain access to its utility functions and environment variables. If no flags are set, the script runs mkdocs serve to start a local documentation server for live preview. If the -b or --build flag is set, the script builds the documentation using mkdocs build and places the output in the site directory.