docs index: correct npm package name; add Python tile

The quickstart still said 'npm install interscript-ts' — the package
is 'interscript'. Python was absent from the runtime tiles; the
phonological-layer tile suggested 'pip install secryst', which is not
our package — now 'pip install interscript-ml'. Links the Libraries
page as the canonical install reference.

Author: ronaldtse

src/pages/docs/index.astro

@@ -33,15 +33,20 @@ interscript -s bgnpcgn-ukr-Cyrl-Latn-2019 <<< "Антон"
         </div>
         <div class="tile card">
           <h3>TypeScript</h3>
-          <pre><code>npm install interscript-ts</code></pre>
+          <pre><code>npm install interscript</code></pre>
           <pre><code>import &#123; transliterate &#125; from "interscript"
 transliterate("bgnpcgn-ukr-Cyrl-Latn-2019", "Антон")
 // =&gt; "Anton"</code></pre>
         </div>
         <div class="tile card">
-          <h3>Phonological layer</h3>
+          <h3>Python</h3>
+          <pre><code>pip install interscript-ml</code></pre>
+          <a href="/docs/libraries">All libraries →</a>
+        </div>
+        <div class="tile card">
+          <h3>Neural models</h3>
           <pre><code>gem install secryst
-# or: pip install secryst / npm i secryst</code></pre>
+# or: pip install interscript-ml</code></pre>
           <a href="/docs/phonological-layer">How vocalization fits →</a>
         </div>
       </div>