Fix #2 List of tags

_includes/functions/wiki-tags.html

@@ -0,0 +1,33 @@
+{%- comment -%}
+=======================
+The following part extracts all the tags from your posts and sort tags, so that you do not need to manually collect your tags to a place.
+=======================
+{%- endcomment -%}
+{%- assign rawtags = "" -%}
+{%- include /functions/wiki-pages.html -%}
+
+{%- for wiki_page in wiki_pages -%}
+	{%- assign ttags = wiki_page.tags | join:'|' | append:'|' -%}
+	{%- assign rawtags = rawtags | append:ttags -%}
+{%- endfor -%}
+{%- assign rawtags = rawtags | split:'|' | sort -%}
+
+{%- comment -%}
+=======================
+The following part removes dulpicated tags and invalid tags like blank tag.
+=======================
+{%- endcomment -%}
+
+{%- assign tags = "" -%}
+{%- for tag in rawtags -%}
+	{%- if tag != "" -%}
+		{%- if tags == "" -%}
+			{%- assign tags = tag | split:'|' -%}
+		{%- endif -%}
+		{%- unless tags contains tag -%}
+			{%- assign tags = tags | join:'|' | append:'|' | append:tag | split:'|' -%}
+		{%- endunless -%}
+	{%- endif -%}
+{%- endfor -%}
+
+{%- assign wiki_tags = tags -%}