Clarify what implementation means

README.md

@@ -520,7 +520,7 @@ Parameters:
     <dt><code>breakpoints</code></dt>
     <dd>Optional. Boolean. Whether to generate copies of the image sized to each Bootstrap breakpoint. Must not use with <code>densities</code>. Only applies to raster images.</dd>
     <dt><code>class</code></dt>
-    <dd>Optional. String. Image class. Merged with implementation.</dd>
+    <dd>Optional. String. Image class. Merged with implementation classes.</dd>
     <dt><code>densities</code></dt>
     <dd>Optional. String. Float numbers suffixed with an "x", delimited by spaces. The pixel densities of the image to generate. There must be at least two. The largest density matches the original image. Examples are <code>"1x 2x"</code>, <code>"1x 1.5x 2x 2.5x 3x"</code>, and <code>"0.5x 1.33x 6x 10x"</code>. Must not use with <code>breakpoints</code>. Only applies to raster images.</dd>
     <dt><code>fetchpriority</code></dt>
@@ -542,7 +542,7 @@ Parameters:
     <dt><code>process</code></dt>
     <dd>Optional. String. Hugo image processing <a href="https://gohugo.io/content-management/image-processing/#image-processing-methods">methods</a> and <a href="https://gohugo.io/content-management/image-processing/#image-processing-options">options</a>, mixed together, for the displayed image. If no method is specified, resize is used. If no image dimensions are specified, the originals are used. If it is <code>"default"</code>, the <a href="https://gohugo.io/content-management/image-processing/#processing-options">default options</a> are used. Only applies to raster images.</dd>
     <dt><code>style</code></dt>
-    <dd>Optional. String. CSS. Image style. Merged with implementation.</dd>
+    <dd>Optional. String. CSS. Image style. Merged with implementation styles.</dd>
     <dt><code>type</code></dt>
     <dd>Optional. String. Type of layout. Must be <code>"grid"</code> or <code>"rows"</code> (default).</dd>
     <dt><code>width</code></dt>
@@ -606,7 +606,7 @@ Parameters:
     <dt><code>srcset</code></dt>
     <dd>Optional. String. Image <a href="https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement/srcset">srcset</a>. Must not use with <code>breakpoints</code> or <code>densities</code>.</dd>
     <dt><code>style</code></dt>
-    <dd>Optional. String. CSS. Image style. Merged with implementation.</dd>
+    <dd>Optional. String. CSS. Image style. Merged with implementation styles.</dd>
     <dt><code>title</code></dt>
     <dd>Optional. String. Plain text. Image title.</dd>
     <dt><code>width</code></dt>