pidgin/nest

Enable OpenGraph and Twitter Cards on all pages and add relevant fields to default archetypes

Testing Done:
Checked on local, confirmed in source that tags appear and populate properly

Bugs closed: NEST-14

Reviewed at https://reviews.imfreedom.org/r/139/
{{- if .IsNamedParams -}}
{{- $scheme := or (.Get "scheme") "https" -}}
{{- $repo := .Get "name" -}}
{{- if eq (.Get "link") "1" -}}<a href="{{print $scheme "://" (index .Site.Data.repos $repo) }}">{{- end -}}
{{- if eq (.Get "short") "1" -}}{{- .Get "name" -}}{{- else -}}{{- index .Site.Data.repos $repo -}}{{- end -}}
{{- if eq (.Get "link") "1" -}}</a>{{- end -}}
{{- else -}}
{{- index .Site.Data.repos (.Get 0) -}}
{{- end -}}