Hello there @MarekMac
This link will help you to do the phone link right.
The Current State of Telephone Links | CSS-Tricks
You also can compress the images to have better performance and for this, you can use the service below. And will be even better if you use a specific image for each device you want to do support.
TinyPNG – Compress PNG images while preserving transparency
Check the HTML code on W3C validator.
Showing results for https://mt-quality.com/ - Nu Html Checker (w3.org)
Take a look in the Lighthouse, if you are using Chrome or Edge the tool is in the developer tools, or you can use it as an extension in the browser. Your site has some issues. In the report, you will find links to articles that will teach you how to fix them.
Lighthouse - Chrome Web Store (google.com)
As a page for business, you may want to share this page and for this, you need to implement open graph meta tags use this tool for testing.
<!-- This is the base configuration -->
<meta property="og:title" content="freeCodeCamp Build a Technical Documentation Page" />
<meta property="og:description"
content="This is a project exercise from freeCodeCamp to get the certification to Responsive Web Design, Build a Technical Documentation Page." />
<meta property="og:type" content="blog" />
<meta property="og:locale" content="en" />
<meta property="og:url" content="https://adrianoenache.dev.br/" />
<!-- This is required by Pinterest -->
<meta property="og:site_name" content="adrianoenache.dev.br" />
<meta property="article:published_time" content="2021-04-19T00:00:00+00:00" />
<meta property="article:author" content="Adriano Enache" />
<!-- This will be used by Facebook, Linkedin and Pinterest -->
<meta property="og:image"
content="https://adrianoenache.dev.br/fcc-projects/fcc-assets/images/og-images/og-image-fb-1200x630-fcc-build-a-technical-documentation-page.jpg" />
<meta property="og:image:width" content="1200" />
<meta property="og:image:height" content="630" />
<!-- This will be used by Twitter -->
<meta name="twitter:card" content="summary" />
<meta name="twitter:site" content="@AdrianoEnache" />
<meta name="twitter:creator" content="@AdrianoEnache" />
<meta name="twitter:title" content="freeCodeCamp Build a Technical Documentation Page" />
<meta name="twitter:description"
content="This is a project exercise from freeCodeCamp to get the certification to Responsive Web Design, Build a Technical Documentation Page." />
<meta name="twitter:image"
content="https://adrianoenache.dev.br/fcc-projects/fcc-assets/images/og-images/og-image-twitter-300x150-fcc-build-a-technical-documentation-page.jpg" />
<meta name="twitter:url" content="https://adrianoenache.dev.br/" />
An important thing to you note is the URL of images needs to have an absolute path.
Font Awesome … I really don´t like this, but is because of the performance issue, you are loading a huge resource and using a few icons. In my opinion, the benefits of using this aren’t good enough by the price your user will pay by access your site.
Instead, you can create your own icon font by using the service below.
IcoMoon App - Icon Font, SVG, PDF & PNG Generator
With this, you will have access to some free icons and you can create your font of icons or you can download the SVG separately. You also can add your own SVG to the set.
More resources are below.
5,775,000+ free and premium vector icons - Iconfinder
HTML Symbols, Entities, Characters and Codes — HTML Arrows (toptal.com)
Free Stock Photos · Pexels
Beautiful Free Images & Pictures | Unsplash
There are more things we can talk about to improve but for now, I think you have a lot to think about this.
@BurningQuestion We always can find something to improve