Fix mustache spec

Signed-off-by: Archer <naarcha@amazon.com>

Author: Naarcha-AWS

spec-insert/lib/renderers/table_renderer.rb

@@ -27,10 +27,8 @@ def initialize(columns, rows, pretty:)
 
   # @return [Array<String>]
   def render_lines
-    \n
     calculate_column_widths if @pretty
     [render_column, render_divider] + render_rows
-    \n
   end
 
   private

spec-insert/lib/renderers/templates/spec_insert.mustache

@@ -3,5 +3,7 @@
 {{{key}}}: {{{value}}}
 {{/arguments}}
 -->
+
 {{{content}}}
+
 <!-- spec_insert_end -->