docs(codeblock): update 'mark' description

Author: curbengh

lib/plugins/tag/code.js

@@ -28,7 +28,7 @@ const rWrap = /\s*wrap:(\w+)/i;
  * @param {Object} line_number Show line number, value must be a boolean
  * @param {Object} highlight Enable code highlighting, value must be a boolean
  * @param {Object} first_line Specify the first line number, value must be a number
- * @param {Object} mark Mark specific line(s), separated by a comma. Specify number range using a dash
+ * @param {Object} mark Line highlight specific line(s), each value separated by a comma. Specify number range using a dash
  * Example: `mark:1,4-7,10` will mark line 1, 4 to 7 and 10.
  * @param {Object} wrap Wrap the code block in <table>, value must be a boolean
  * @returns {String} Code snippet with code highlighting