Soften wording in demo

The previous version seemed a little bit OTT.

Author: csswizardry

demo/index.html

@@ -457,7 +457,7 @@ <h2 id=section:installation>Installation</h2>
   install Obs.js any other way—via a package manager, as an external file—will
   cause Obs.js to self-terminate.</p>
 
-  <p>In order for Obs.js to provide any value at all, it needs to run before any
+  <p>In order for Obs.js to provide its key function, it needs to run before any
   other HTML, CSS, or JS that might depend on it. Thus, Obs.js must be installed
   early and synchronously. <q>Early and synchronously</q>, usually means
   <em>slow</em>, but by pasting Obs.js as an inline <code>&lt;script&gt;</code>,