Upgrade Font Awesome to 6.4.2 (#237)

* Upgrade Font Awesome to 6.4.2

* Minimize changes

community.html

@@ -13,7 +13,7 @@ <h1>Meet the Scrapy community</h1>
   <p>Scrapy has a healthy and active community. Check the places where you can get help and find the latests Scrapy news.</p>
 
   <div class="community-box">
-    <h2><i class="fa fa-github"></i>Getting involved</h2>
+    <h2><i class="fa-brands fa-github"></i>Getting involved</h2>
     <hr />
     <p>
       If you want to get involved and contribute with patches or documentation,
@@ -25,7 +25,7 @@ <h2><i class="fa fa-github"></i>Getting involved</h2>
 
   <div class="community-box">
     <a href="http://reddit.com/r/scrapy">
-      <h2><i class="fa fa-reddit-alien"></i> /r/scrapy subreddit</h2>
+      <h2><i class="fa-brands fa-reddit"></i> /r/scrapy subreddit</h2>
     </a>
     <hr />
     <p>
@@ -38,7 +38,7 @@ <h2><i class="fa fa-reddit-alien"></i> /r/scrapy subreddit</h2>
 
   <div class="community-box">
     <a href="http://stackoverflow.com/questions/tagged/scrapy">
-      <h2><i class="fa fa-stack-overflow"></i> StackOverflow</h2>
+      <h2><i class="fa-brands fa-stack-overflow"></i> StackOverflow</h2>
     </a>
     <hr />
     <p>
@@ -51,7 +51,7 @@ <h2><i class="fa fa-stack-overflow"></i> StackOverflow</h2>
 
   <div class="community-box">
     <a href="https://discord.gg/mv3yErfpvq">
-      <h2><i class="fa fa-discord"></i> Discord <sup>NEW</sup></h2>
+      <h2><i class="fa-brands fa-discord"></i> Discord <sup>NEW</sup></h2>
     </a>
     <hr />
     <p>
@@ -61,7 +61,7 @@ <h2><i class="fa fa-discord"></i> Discord <sup>NEW</sup></h2>
   </div>
 
   <div class="community-box">
-    <h2><i class="fa fa-comments-o"></i>IRC Channel</h2>
+    <h2><i class="fa fa-comments"></i>IRC Channel</h2>
     <hr />
     <p>
       If Discord is not for you, you can also join the
@@ -74,7 +74,7 @@ <h2><i class="fa fa-comments-o"></i>IRC Channel</h2>
 
   <div class="community-box">
     <a href="http://twitter.com/ScrapyProject">
-      <h2><i class="fa fa-twitter"></i> Scrapy tweets</h2>
+      <h2><i class="fa-brands fa-twitter"></i> Scrapy tweets</h2>
     </a>
     <hr />
     <p>
@@ -85,7 +85,7 @@ <h2><i class="fa fa-twitter"></i> Scrapy tweets</h2>
 
   <div class="community-box">
     <a href="https://t.me/scrapy_python">
-      <h2 class="small-title"><i class="fa fa-telegram"></i>Telegram Russian Community</h2>
+      <h2 class="small-title"><i class="fa-brands fa-telegram"></i>Telegram Russian Community</h2>
     </a>
     <hr />
     <p>