feat: remove shadow mixin, dont highlight single letters

public/scss/mixins.scss

@@ -73,8 +73,3 @@
 	line-height: $size;
 	font-size: $font-size;
 }
-
-@mixin box-shadow($shadow){
-	-webkit-box-shadow: $shadow;
-	box-shadow: $shadow;
-}

public/src/modules/search.js

@@ -310,6 +310,7 @@ define('search', ['translator', 'storage', 'hooks', 'alerts'], function (transla
 		}
 		searchQuery = utils.escapeHTML(searchQuery.replace(/^"/, '').replace(/"$/, '').trim());
 		const regexStr = searchQuery.split(' ')
+			.filter(word => word.length > 1)
 			.map(function (word) { return utils.escapeRegexChars(word); })
 			.join('|');
 		const regex = new RegExp('(' + regexStr + ')', 'gi');