JSFiddle - React, Tailwind, and code Playground

HTML

<template id="custom-template">
        <h1><%tags%></h1>
        <h2><%height%></h2>
        <h3><%testing%></h3>
        <h3><%testing%></h3>
        <h3><%testing%></h3>
        <h3><%testing%></h3>
        <h3><%testing%></h3>
        <h2><%height%></h2>
        <p><%something%></p>
        <p><%more%></p>
        <p><%example%></p>
    </template>

JavaScript

var TemplateEngine = function(tpl, data) {
  var re = /(?:&lt;|<)%(.*?)(?:%&gt;|>)/g, match;
  return tpl.replace(re, function($0, $1) { 
     return data[$1] ? data[$1] : $0;
  });
}

var template = $('#custom-template').html();

console.log(TemplateEngine(template, {
  tags: "Krasimir",
  height: 29,
  testing: "whatever",
  something: "hi",
  more: "even more content",
  example: "even more!"
}));