Add 1.4 and 1.3 manuals to website (fix #866)

docs/content/3.manual/manual.yml

@@ -1,5 +1,11 @@
 ---
-headline: jq Manual
+headline: jq Manual (development version)
+
+history: |
+
+  *For released versions, see [jq 1.4](/jq/manual/v1.4) or
+  [jq 1.3](/jq/manual/v1.3).*
+
 body: |
 
   A jq program is a "filter": it takes an input, and produces an

docs/templates/manual.liquid

@@ -57,6 +57,7 @@
         </div>
         <div class="span9">
           <h1>{{headline}}</h1>
+          {{ history | markdownify }}
           {{ body | markdownify }}
           {% for section in sections %}
             <section id="{{section.title | sanitize}}">