Remove microdata from feeds

It's useless and invalid in those contexts, and removing it
significantly trims the file sizes.

Edit a post featuring a microdata code snippet to avoid conflicts.

content/posts/website-best-practices.md

@@ -1010,7 +1010,7 @@ When setting max line lengths, use a CSS media query to ensure that printed vers
     padding: 0 3%;
   }
 
-  div[itemprop="articleBody"] {
+  div[itemprop='articleBody'] {
     margin: auto;
     max-width: 36em;
   }

layouts/_default/list.atom.xml

@@ -28,7 +28,7 @@
     <rights>CC-BY-SA 4.0 by Rohan Kumar</rights>
 		<content type="xhtml">
 			<div xmlns="http://www.w3.org/1999/xhtml">
-					{{ partial "processed-content.html" . | safeHTML }}
+					{{ partial "processed-content.html" . | replaceRE `(?: )?item(scope|prop|id|ref)="[^"]*"` "" | safeHTML }}
 			</div>
 		</content>
 		<object-type xmlns="http://activitystrea.ms/spec/1.0/">

layouts/_default/rss.xml

@@ -35,7 +35,7 @@
       <pubDate>{{ .Date.Format "Mon, 02 Jan 2006 15:04:05 -0700" | safeHTML }}</pubDate>
       {{ with .Site.Author.email }}<author>{{.}}{{ with $.Site.Author.name }} ({{.}}){{end}}</author>{{end}}
       <guid>{{ .Permalink }}</guid>
-      <description>{{- .Content | html -}}</description>
+      <description>{{- .Content | replaceRE `(?: )?item(scope|prop|id|ref)="[^"]*"` "" | html -}}</description>
     </item>
     {{ end }}
     {{ end }}