Don't add ellipses to search excerpt when at start/end

If the excerpt starts at the start of the content, ellipses will not be prepended;
if the excerpt ends at the end of the content, ellipses will not be appended

src/assets/js/search.js

@@ -88,7 +88,7 @@
             `<h3 class="search-results__result-title">${item.title}</h3>` +
           '</a>' +
           (breadcrumbs.length ? `<div class='search-results__result-breadcrumbs'>${breadcrumbsString}</div>` : '') +
-          `<p class="search-results__result-excerpt">...${excerpt}...</p>` +
+          `<p class="search-results__result-excerpt">${excerpt}</p>` +
         '</li>'
     })
 
@@ -99,10 +99,13 @@
     const queryRegex = new RegExp(query, 'i')
     const searchIndex = content.search(queryRegex)
     const queryLength = query.length
-    const excerpt = content.slice(
-      getStartIndex(searchIndex, content),
-      getEndIndex(searchIndex, queryLength, content)
-    )
+
+    const excerptStartIndex = getStartIndex(searchIndex, content)
+    const excerptEndIndex = getEndIndex(searchIndex, queryLength, content)
+    let excerpt = content.slice(excerptStartIndex, excerptEndIndex)
+
+    if (excerptStartIndex > 0) { excerpt = '...' + excerpt }
+    if (excerptEndIndex < content.length) { excerpt += '...' }
 
     return excerpt.replace(
       queryRegex,