refactor: convert i to em

In earlier versions of the HTML specification, the <i> element was merely a presentational element used to display text in italics, much like the <b> element was used to display text in bold letters. This is no longer true, as these tags now define semantics rather than typographic appearance. A browser will typically still display the contents of the <i> element in italic type, but is, by definition, no longer required to do so. To display text in italic type, authors should use the CSS font-style property.

src/pages/documentation/policy/metadata.astro

@@ -75,7 +75,7 @@ const page: IStandardPageMetadata = {
   </Section>
   <Section {...page.section[3]}>
     <p>
-      The summary should <i>briefly</i> explain the dataset in under 250 characters (an ArcGIS Online limitation). It is
+      The summary should <em>briefly</em> explain the dataset in under 250 characters (an ArcGIS Online limitation). It is
       primarily used when reviewing ArcGIS Online search results. The summary may end up being very similar to the dataset
       name for some datasets.
     </p>