Changes

• Add render CLI command for rendering a single file to stdout (with --no-template flag)
• Add -m/--site-module option to load site from a Lua module instead of site.moon file
• Add config function in site scope to update site config dynamically
• Template directory is now lazily evaluated, allowing dynamic changes via config
• Add cache disable support (used internally by render command)
• Change: enable UTF8 validation, normalization, smart punctuation, and unsafe HTML