Merge pull request #2113 from jadejs/jstransformer-docs

Add instructions to install the jstransformer one needs

docs/views/reference/filters.jade

@@ -15,6 +15,15 @@ block documentation
   p.
     Check out the documentation for the JSTransformer for the options
     supported for the specific filter.
+  p.
+    After you have located which JSTransformer is useful for you
+    as a Jade filter, simply install it through npm in your project
+    directory:
+  pre.
+    npm install --save jstransformer-coffee-script
+    npm install --save jstransformer-markdown-it
+  p.
+    Now, you should be able to render the following template:
 
   .row
     .col-lg-6