Fix missing <item> tag and remove unnecessary whitespace from feed generation

feed.xml

@@ -5,19 +5,16 @@
       <link>https://hugot.nl/blog.html</link>
       <description>Hugo's personal blog</description>
       <language>en-us</language>
-      <pubDate>Sat 08 Feb 2020 09:58:35 AM CET</pubDate>
-      <lastBuildDate>Sat 08 Feb 2020 09:58:35 AM CET</lastBuildDate>
+      <pubDate>Sat 08 Feb 2020 10:07:44 AM CET</pubDate>
+      <lastBuildDate>Sat 08 Feb 2020 10:07:44 AM CET</lastBuildDate>
       <docs>http://blogs.law.harvard.edu/tech/rss</docs>
       <generator>Hugo's Custom Bash Script</generator>
       <managingEditor>social@hugot.nl</managingEditor>
       <webMaster>infra@hugot.nl</webMaster>
-<title>  Introduction  </title>
-<description> Hello, welcome to my blog! My name is Hugo. I am a 22 year old Software
+<item><title> Introduction </title><description>Hello, welcome to my blog! My name is Hugo. I am a 22 year old Software
 Engineering student from the Netherlands. Software development is a huge part
 of my life, I write a lot of (weird) programs to scratch my own itch and most
 software I create is open_source by default. I also run a one-man company that
-provides some IT services on the side. </description>
-<pubDate> Sat 08 Feb 2020 09:30:06 AM CET </pubDate>
-<guid> ./posts/introduction/index.html#MjM3MzUyOTAwNSA5MDYK </guid>
+provides some IT services on the side.</description><pubDate>Sat 08 Feb 2020 09:30:06 AM CET</pubDate><guid>./posts/introduction/index.html#MjM3MzUyOTAwNSA5MDYK</guid></item>
 </channel>
 </rss>

generate-blog.bash

@@ -115,7 +115,9 @@ el-enclose() {
     element_name="$1"
     shift
 
-    echo "<$element_name>" "$@" "</$element_name>"
+    printf '%s' "<$element_name>"
+    printf '%s' "$@"
+    printf '%s' "</$element_name>"
 }
 
 site_url="https://hugot.nl"
@@ -173,10 +175,13 @@ while read -r post_html; do
     } >> "$new_html"
 
     {
+        el item
         el-enclose title "$title"
         el-enclose description "$excerpt"
         el-enclose pubDate "$pubdate"
         el-enclose guid "${href}#$(base64 <(cksum <<<"$text"))"
+
+        el-close item
     } >> "$new_rss"
 done < "$posts_file"