Readme: Added Node and npm version requirements (#2790)

README.md

@@ -27,6 +27,13 @@ Prism depends on community contributions to expand and cover a wider array of us
 
 Thank you so much for contributing!!
 
+### Software requirements
+
+Prism will run on [almost any browser](https://prismjs.com/#features-full) and Node.js version but you need the following software to contribute:
+
+- Node.js >= 10.x
+- npm >= 6.x
+
 ## Translations
 
 * [简体中文](https://www.awesomes.cn/repo/PrismJS/prism) (if unavailable, see [here](https://deepmind.t-salon.cc/article/113))

docs/index.html

@@ -72,6 +72,12 @@
 <li>Go to <a href="https://github.com/PrismJS/prism-themes">prism-themes</a> if you want to add a new theme.</li>
 </ul>
 <p>Thank you so much for contributing!!</p>
+<h3>Software requirements</h3>
+<p>Prism will run on <a href="https://prismjs.com/#features-full">almost any browser</a> and Node.js version but you need the following software to contribute:</p>
+<ul>
+<li>Node.js &gt;= 10.x</li>
+<li>npm &gt;= 6.x</li>
+</ul>
 <h2>Translations</h2>
 <ul>
 <li><a href="https://www.awesomes.cn/repo/PrismJS/prism">简体中文</a> (if unavailable, see <a href="https://deepmind.t-salon.cc/article/113">here</a>)</li>