set post date based on git

eleventy.config.cjs

@@ -20,4 +20,8 @@ module.exports = function(eleventyConfig){
 	eleventyConfig.addDataExtension("yml, yaml",
 		contents => require('js-yaml').load(contents)
 	)
+
+	if(process.env.NODE_ENV==="production"){
+		eleventyConfig.addGlobalData('date', 'git Last Modified');
+	}
 }