Add Plugin docs in ascii format

Fixes #1741

docs/plugin-doc.asciidoc.erb

@@ -1,3 +1,4 @@
+<%- plugin_name = name -%>
 [[plugins-<%= section %>s-<%= name %>]]
 === <%= name %>
 
@@ -21,7 +22,8 @@ These are the config options
        is_regexp = false
      end
 -%>
-===== <%= name %><%= " (required setting)" if config[:required] %><%= " (DEPRECATED)" if config[:deprecated] %>
+[[plugins-<%= section%>s-<%= plugin_name%>-<%= name%>]]
+===== `<%= name %>` <%= " (required setting)" if config[:required] %><%= " (DEPRECATED)" if config[:deprecated] %>
 
 <% if config[:deprecated] -%>
   * DEPRECATED WARNING: This config item is deprecated. It may be removed in a further version.
@@ -30,14 +32,14 @@ These are the config options
   * The configuration attribute name here is anything that matches the above regular expression.
 <% end -%>
 <% if config[:validate].is_a?(Symbol) -%>
-  * Value type is <<configuration,_<%= config[:validate] %>, <%= config[:validate] %>>>
+  * Value type is <<<%= config[:validate] %>,<%= config[:validate] %>>>
 <% elsif config[:validate].nil? -%>
-  <li> Value type is <a href="../configuration#string">string</a>
+  <li> Value type is <<string,string>>
 <% elsif config[:validate].is_a?(Array) -%>
-  * Value can be any of: <%= config[:validate].map(&:inspect).join(", ") %>
+  * Value can be any of: `<%= config[:validate].join('`, `') %>`
 <% end -%>
 <% if config.include?(:default) -%>
-  * Default value is <%= config[:default].inspect %>
+  * Default value is `<%= config[:default].inspect %>`
 <% else -%>
   * There is no default value for this setting.
 <% end -%>
@@ -45,7 +47,3 @@ These are the config options
 <%= config[:description] %>
 
 <% end -%>
-
-This is documentation from <a href="https://github.com/logstash/logstash/blob/v<%= LOGSTASH_VERSION %>/<%= file %>"><%= file %></a>
-
-<h3>Milestone: <a href="../plugin-milestones"><%= @milestone %></a></h3>

docs/plugin-synopsis.asciidoc.erb

@@ -1,4 +1,18 @@
-[cols="<,<,<,<",options="header",]
+<%- plugin_name = name -%>
+[source,json]
+--------------------------
+<%= name %> {
+<% sorted_attributes.each do |name, config|
+   next if config[:deprecated]
+   next if !config[:required]
+-%>
+<%= "  " if section == "codec" %>    <%= name %> => ... 
+<% end -%>
+<%= "  " if section == "codec" %>  }
+
+--------------------------
+
+[cols="<,<,<,<m",options="header",]
 |=======================================================================
 |Setting |Input type|Required/optional|Default value
 <% sorted_attributes.each do |name, config|
@@ -7,8 +21,8 @@
      annotation = "|string, one of #{config[:validate].inspect}"
    elsif config[:validate] == :path
      annotation = "|a valid filesystem path"
-   else 
-     annotation = "|#{config[:validate]}"
+   else
+     annotation = "|<<#{config[:validate]},#{config[:validate]}>>"
    end
 
    if name.is_a?(Regexp)
@@ -20,11 +34,15 @@
      annotation += "|optional"
    end
    if config.include?(:default)
-     annotation += "|#{config[:default].inspect}"
+     if config[:default].is_a?(String)
+       annotation += "|`#{config[:default]}`"
+     else
+       annotation += "|#{config[:default].inspect}"
+     end
    else 
      annotation += "|"
    end
 -%>
-| <<_<%= name %>,<%= name %>>> <%= annotation %>
+| <<plugins-<%= section %>s-<%=plugin_name%>-<%= name %>>> <%= annotation %>
 <% end -%>
 |=======================================================================