clarify repo sync on unreliable connections

static/build.html

@@ -226,8 +226,8 @@ repo init -u https://github.com/GrapheneOS/platform_manifest.git -b 10
 repo sync -j32</pre>
 
             <p>If your network is unreliable and <code>repo sync</code> fails, you can run the
-            <code>repo sync</code> command again as many times as needed for it to fully
-            succeed.</p>
+            <code>repo sync</code> command again to continue from where it was interrupted. It
+            handles connection failures robustly and you shouldn't start over from scratch.</p>
 
             <h2 id="stable-release">
                 <a href="#stable-release">Stable release</a>