Make some page settings also configurable site wide (#182)

Adds **local** and **global** param to following front-matter vars:
- hideMeta
- ShowToc
- TocOpen
- comments

Co-authored-by: Aditya Telange <21258296+adityatelange@users.noreply.github.com>

layouts/_default/search.html

@@ -8,7 +8,7 @@
             <line x1="21" y1="21" x2="16.65" y2="16.65"></line>
         </svg>
     </h1>
-    {{- if .Params.hideMeta }}{{ else }}
+    {{- if not (.Param "hideMeta") }}
     <div class="post-meta">
         {{- if .IsTranslated -}}
         <ul class="i18n_list">

layouts/_default/single.html

@@ -9,7 +9,7 @@
     <div class="post-description">
       {{ .Description }}
     </div>
-    {{- if .Params.hideMeta }}{{ else }}
+    {{- if not (.Param "hideMeta") }}
     <div class="post-meta">
       {{- partial "post_meta.html" . -}}
       {{- if .IsTranslated -}}&nbsp;|&nbsp;
@@ -33,9 +33,9 @@
   </header>
   {{- $isHidden := ((.Site.Params.cover.hidden | default .Site.Params.cover.hiddenInSingle) | default .Params.cover.hidden )}}
   {{- partial "cover.html" (dict "cxt" . "IsHome" false "isHidden" $isHidden) }}
-  {{- if .Params.ShowToc }}
+  {{- if (.Param "ShowToc") }}
   <div class="toc">
-    <details {{if .Params.TocOpen }} open{{ end }}>
+    <details {{if (.Param "TocOpen") }} open{{ end }}>
       <summary accesskey="c" title="(Alt + C)">
         <div class="details">{{- i18n "toc" | default "Table of Contents" }}</div>
       </summary>
@@ -61,7 +61,7 @@
     {{- end }}
   </footer>
 
-  {{- if and ($.Site.Params.comments) (ne .Params.comments false) }}
+  {{- if (.Param "comments") }}
   {{- partial "comments.html" . }}
   {{- end }}
 </article>