Update docs

Author: JayPanoz

docs/CSS28-migration_guide.md

@@ -235,11 +235,11 @@ They accept the same values as the CSS property `padding`.
 
 ## Ligatures moved to the global space
 
-As of version `2.0.0-beta.21`, ligatures are no longer limited to RTL (arabic and farsi scripts). The setting is now available in Latin scripts as well.
+As of version `2.0.0-beta.22`, ligatures are no longer limited to RTL (arabic and farsi scripts). The setting is now available in Latin scripts as well.
 
 ## Experimental Web Publications stylesheet
 
-As of version `2.0.0-beta.21`, ReadiumCSS provides an experimental stylesheet for Web Publications. It ships with the following features:
+As of version `2.0.0-beta.22`, ReadiumCSS provides an experimental stylesheet for Web Publications. It ships with the following features:
 
 - font-family
 - font variations (weight, width, optical-sizing)

docs/ReadiumCSS_docs.epub

@@ -285,13 +285,13 @@ const backgroundColor = defaultColors.RS__backgroundColor;</code></pre>
     <section id="ligatures-moved" class="level2">
       <h2 id="sigil_toc_id_217">Ligatures moved to the global space</h2>
 
-      <p>Since version <code>2.0.0-beta.21</code>, ligatures are no longer limited to RTL (arabic and farsi scripts). The setting is now available in Latin scripts as well.</p>
+      <p>Since version <code>2.0.0-beta.22</code>, ligatures are no longer limited to RTL (arabic and farsi scripts). The setting is now available in Latin scripts as well.</p>
     </section>
 
     <section id="experimental-web-publications-stylesheet" class="level2">
       <h2 id="sigil_toc_id_218">Experimental Web Publications stylesheet</h2>
 
-      <p>Since version <code>2.0.0-beta.21</code>, ReadiumCSS provides an experimental stylesheet for Web Publications. It ships with the following features:</p>
+      <p>Since version <code>2.0.0-beta.22</code>, ReadiumCSS provides an experimental stylesheet for Web Publications. It ships with the following features:</p>
 
       <ul>
         <li>font-family</li>