Add support for utterrances label (#384)

* Support utterrances label

* Update CONTRIBUTORS.md

Co-authored-by: Luiz F. A. de Prá <luizdepra@users.noreply.github.com>

CONTRIBUTORS.md

@@ -72,3 +72,4 @@
 - [Rajiv Ranjan Singh](https://iamrajiv.github.io/)
 - [Pakhomov Alexander](https://github.com/PakhomovAlexander)
 - [Rhys Perry](https://rhysperry.com)
+- [Arunvel Sriram](https://github.com/arunvelsriram)

layouts/partials/posts/utterances.html

@@ -3,6 +3,7 @@
   <script src="https://utteranc.es/client.js"
     repo= "{{ .Site.Params.utterances.repo }}"
     issue-term="{{ default "title" .Site.Params.utterances.issueTerm }}"
+    {{ if isset .Site.Params.utterances "label" }}label="{{ .Site.Params.utterances.label }}"{{ end }}
     theme="{{ default "github-light" .Site.Params.utterances.theme }}"
     crossorigin="anonymous"
     async>