Adds RSS feed for the blog (#168)

Signed-off-by: Vishnu Bharathi P <vishnubharathi04@gmail.com>

layouts/partials/blog/hero.html

@@ -7,6 +7,11 @@
       <h1 class="title is-size-1 is-size-2-mobile has-text-white has-text-weight-light{{ if $author }} is-spaced{{ end }}">
         {{ .Title }}
       </h1>
+
+      {{ if eq .RelPermalink "/blog/" }}
+      <a href="/blog/index.xml"><i class="fa fa-rss"></i> &nbsp; Subscribe via RSS</a>
+      {{ end }}
+
       {{ with $author }}
       <p class="subtitle is-size-3 is-size-4-mobile has-text-white-bis has-text-weight-light">
         {{ . | markdownify }}

layouts/partials/meta.html

@@ -1,6 +1,8 @@
 {{ $favicon := site.Params.favicon | relURL }}
+{{ $rssFeed := "blog/index.xml" | absURL }}
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 {{ hugo.Generator }}
 
 <link rel="shorcut icon" href="{{ $favicon }}">
+<link rel="alternate" type="application/rss+xml" href="{{ $rssFeed }}" title="TiKV"/>