title: Automating a text change on every html page of a website
body: <p>I'm using Siteimprove which is a software that looks through a website and recommends accessibility changes. I'm supposed to go through and edit the html of the pages to improve the Siteimprove score. </p>
  
  <p>I'm supposed to add a language attribute to all 143 pages and I was thinking I could write a simple script to go through every html page and replace <code>&lt;html&gt;</code> with <code>&lt;html lang="en-US"&gt;</code> instead of manually do this. </p>
  
  <p>I haven't done this before so I was thinking to make a copy and test a script (I have yet to write). Do you know where I should look for examples to write such a script that would basically say:</p>
  
  <p>"For every file in directory named .html, if it contains <code>&lt;html&gt;</code> replace <code>&lt;html&gt;</code> with <code>&lt;html lang="en-US"&gt;</code>" </p>
  
  <p>Or if I should edit my logic statement above? I'm a student worker and don't want to mess this up.</p>