Update velociraptor doc

I have updated the doc with the steps that I have done to use velociraptor. I will open a few issues in the velociraptor in order to solve some problems.

By the way, do you have a branch of swift where you changed libstf to libvelociraptor?

doc/RTD/source/VELOCIraptorInterface/stfalone.rst

@@ -23,24 +23,18 @@ git repository as::
   git clone https://github.com/pelahi/VELOCIraptor-STF
 
 Similar to the SWIFT with VELOCIraptor configuration, we can use the 
-swift-interface branch to analyse individual snapshots. We can use this branch
+master to analyse individual snapshots. We can use this branch
 by doing::
 
   cd VELOCIraptor-STF
   git fetch
-  git checkout swift-interface
 
-Again we need to copy the default SWIFT config file to a other config file by
-doing::
+Again we need to configure VELOCIraptor::
 
-  cd stf
-  cp Makefile.config.SWIFT-template Makefile.config
+  cmake . -DVR_USE_GAS=ON
 
-Similar to configuring VELOCIraptor with swift we need to change the first 20
-lines of ``Makefile.config`` to work with our compiler, but we also need to 
-change the fact that we do not use the swift-interface but the standalone 
-version of the code, so change ``SWIFTINTERFACE="on"`` to 
-``SWIFTINTERFACE="off"``.
+In this case, we do not need the SWIFT interface, therefore we can drop
+this option (disabled by default).
 
 Compiling VELOCIraptor
 ----------------------
@@ -50,9 +44,7 @@ configuration with SWIFT. In this case we can compile the code as::
 
   make 
 
-After this an additional folder is created in ``VELOCIraptor-stf/stf`` called
-``bin``, in which the binary files of ``stf-gas`` is present (assuming you 
-run a simulation with SPH [#nosph]_)
+After this an executable is created (``VELOCIraptor-stf/stf``).
 
 Running VELOCIraptor on a Snapshot
 ----------------------------------
@@ -61,10 +53,12 @@ After the code is compile the next step is using VELOCIraptor on a single
 snapshot of a simulation. The code has several options which can be used, which
 can be displayed by running a terminal command of an invalid letter like::
 
-  ./stf-gas -h
+  ./stf -h
 
 which gives the information about the usage of the command::
 
+  VELOCIraptor/STF running with MPI. Number of mpi threads: 1
+  VELOCIraptor/STF running with OpenMP. Number of openmp threads: 8
   USAGE:
 
   -C <configuration file (overrides other options)> 
@@ -80,13 +74,6 @@ which gives the information about the usage of the command::
    ===== EXTRA OPTIONS REQUIRED FOR RAMSES INPUT ====== 
   -t <ramses snapnumber>
 
-After this we can run a VELOCIraptor on a snapshot as::
+After this we can run VELOCIraptor on a snapshot as::
   
-  ./stf-gas -i input -o output -C configfile.txt
-
-
-.. [#nosph] In the case that in the ``Makefile.config`` it is indicate that the 
-   simulation does only contain dark matter this will reflect back on the 
-   generated binary file. So ``stf-gas`` will change to ``stf`` in the case of 
-   a dark matter only simulation.
-
+  ./stf -i input -o output -C configfile.txt