resolves #17 publish the language support scripts and load into browser, if required (proposal 3)
- create helper function to vendor JS file in UI catalog, with option to concatenate JS files
- add MultiFileReadStream class
- vendor the scripts from lunr-languages as lunr-languages.js if non-en languages are enabled
- set the SITE_SEARCH_LANGUAGES env var to a comma-separated list of non-en languages if non-empty
- change search-script ID to search-ui-script to match filename
- rename lunrSiteSearch.init to initSearch
- check for globalThis properly