add astro to docs

doc/book.html

@@ -1326,11 +1326,11 @@ <h1 id="getstarted" class="h1" data-heading-depth="1" style="display:block;font-
 <a href="https://github.com/koka-lang/koka" data-linkid="kokarepo" class="button learn" target="_top">Github</a>
 <a href="https://koka-lang.github.io/koka/doc/toc.html" data-linkid="libraries" class="button learn" target="_top">Libraries</a></p>
 <div class="smaller" style="font-size:smaller">
-<p class="p noindent">Note: Koka v2 is a research language that is currently under development
+<p class="p noindent">Note: Koka v3 is a research language that is currently under development
 and not ready for production use.
 Nevertheless, the language is stable and the compiler
 implements the full specification. The main things lacking at the moment are
-libraries, package management, and deep IDE integration.
+(async) libraries and package management.
 </p>
 <div class="news">
 <p class="p noindent">News: