Merge intro / TOC

doc/sphinx/users-guide/vcl-intro.rst

-Varnish Configuration Language - VCL
--------------------------------------
-
-Varnish has a great configuration system. Most other systems use
-configuration directives, where you basically turn on and off lots of
-switches. Varnish uses a domain specific language called Varnish
-Configuration Language, or VCL for short. Varnish translates this
-configuration into binary code which is then executed when requests
-arrive.
-
-The VCL files are divided into subroutines. The different subroutines
-are executed at different times. One is executed when we get the
-request, another when files are fetched from the backend server.
-
-Varnish will execute these subroutines of code at different stages of
-its work. Because it is code it is execute line by line precedence
-isn't a problem. At some point you call an action in this subroutine
-and then the execution of the subroutine stops.
-
-If you don't call an action in your subroutine and it reaches the end
-Varnish will execute some built in VCL code. You will see this VCL
-code commented out in default.vcl.
-
-99% of all the changes you'll need to do will be done in two of these
-subroutines. *vcl_recv* and *vcl_fetch*.
-
-
-.. _users-guide-vcl_fetch_actions:
-
-

doc/sphinx/users-guide/vcl.rst

-VCL
----
+VCL - Varnish Configuration Language
+------------------------------------
 
+Varnish has a great configuration system. Most other systems use
+configuration directives, where you basically turn on and off lots of
+switches. Varnish uses a domain specific language called Varnish
+Configuration Language, or VCL for short. 
 
-Yes. Is great. Ja.
+Every inbound request flows through Varnish and you can influence how
+the request is being handled by altering the VCL code. You can direct
+certain requests to certains backends, you can alter the requests and
+the responses or have Varnish take various actions depending on
+arbitrary properties of the request or the response. This makes
+Varnish an extremly powerful HTTP processor, not just for caching.
 
+Varnish translates VCL into binary code which is then executed when
+requests arrive. The performance impact of VCL is negligible.
+
+The VCL files are organized into subroutines. The different subroutines
+are executed at different times. One is executed when we get the
+request, another when files are fetched from the backend server.
+
+If you don't call an action in your subroutine and it reaches the end
+Varnish will execute some built in VCL code. You will see this VCL
+code commented out in default.vcl that ships with Varnish Cache.
+
+.. _users-guide-vcl_fetch_actions:
 
 .. toctree::
    :maxdepth: 2
 
-   vcl-intro
    vcl-syntax
    vcl-built-in-subs
    vcl-variables