Docs update

docs/howto/athena.yaml

 spack:
-    specs:
-    - acts@13 +dd4hep +digitization +examples +fatras +geant4 +identification +json +tgeo +ipo
-    - boost@1.76.00
-    - cmake
-    - clhep cxxstd=17
-    - dd4hep +geant4 +assimp +hepmc3 +lcio +ipo
-    - eigen
-    - gaudi@36.0 +ipo
-    - geant4 +ipo +qt +opengl -python +threads +vecgeom cxxstd=17
-    - genfit +ipo
-    - hepmc3 +interfaces +python +rootio        
-    - lcio +ipo
-    - mesa -llvm swr=none
-    - nano
-    - podio +ipo
-    - pythia8 +fastjet
-    - root cxxstd=17 +fftw +fortran +gdml +mlp +pythia8 +root7 +tmva +vc +xrootd +ssl
-    - xrootd cxxstd=17 +python
-    - npdet +geocad
-    - eicd
-    - log4cxx
-    - afterburner +zlib +root
-    - juggler
-    - athena-eic +reconstruction
-    - py-pandas
-    - py-matplotlib
-    concretization: together
-    config:
-        install_missing_compilers: true
+  specs:
+  - acts@13 +dd4hep +digitization +examples +fatras +geant4 +identification +json
+    +tgeo +ipo
+  - boost@1.76.00
+  - cmake
+  - clhep cxxstd=17
+  - dd4hep +geant4 +assimp +hepmc3 +lcio +ipo
+  - eigen
+  - gaudi@36.0 +ipo
+  - geant4 +ipo +qt +opengl -python +threads +vecgeom cxxstd=17
+  - genfit +ipo
+  - hepmc3 +interfaces +python +rootio
+  - lcio +ipo
+  - mesa -llvm swr=none
+  - podio +ipo
+  - root cxxstd=17 +fftw +fortran +gdml +mlp +pythia8 +root7 +tmva +vc +xrootd +ssl
+  - xrootd cxxstd=17 +python
+  - npdet +geocad
+  - eicd
+  - log4cxx
+  - afterburner +zlib +root
+  - juggler
+  - athena-eic +reconstruction
+  - py-pandas
+  - py-matplotlib
+  concretization: together
+  config:
+    install_missing_compilers: true
+  view: true
         # install_tree:
         # root: /opt/software
-    #view: /opt/local
\ No newline at end of file
+    #view: /opt/local

docs/howto/export_to_step.rst

+Geometry export to STEP
+=======================
+
+In order to export the geometry to STEP there is `npdet_to_step` app which is a part of npdet.
+
+
+.. code:: bash
+
+    # To list parts names one can use list command:
+    npdet_to_step list athena.xml
+
+    # To export a particular detector:
+    npdet_to_step part -l 100 negative_ecal athena.xml

docs/howto/full_simulation.rst

@@ -7,7 +7,7 @@ Tutorials
 Tutorials are available on a dedicated websites:
 
 Detector simulation
-~~~~~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^^^^^
 
 - `Full simulation tutorials <https://eic.phy.anl.gov/tutorials/eic_tutorial/getting-started/quickstart>`_
 - `Quick start guide <https://eic.phy.anl.gov/tutorials/eic_tutorial/getting-started/quickstart>`_
@@ -18,7 +18,7 @@ Detector simulation
 `Perticipate in feedback! <https://docs.google.com/forms/d/e/1FAIpQLSclPBXv13pVtawt35XeaCDMOcmdo8fhKTapdmjFO_6gPTV-8w/viewform?usp=sf_link>`_
 
 Tracking
-~~~~~~~~
+^^^^^^^^
 
 - `(in development) ACTS tracking repo <https://eicweb.phy.anl.gov/EIC/documentation/guide_to_tracking>`_
 
@@ -31,7 +31,7 @@ Particle gun
 There are at least 2 ways of running a particle gun out of the box:
 
 - using npsim command line
-- using geant macro file and invoke gps
+- using geant macro file and invoke GPS (General Particle Source)
 
 
 Using npsim (wrapper around ddsim) command line: 
@@ -46,6 +46,17 @@ Using npsim (wrapper around ddsim) command line:
     npsim --compactFile=athena.xml -N=2 --random.seed 1 --enableGun --gun.energy 2*GeV --gun.thetaMin 0*deg --gun.thetaMax 90*deg --gun.distribution uniform --outputFile test.root
 
 
+Using GPS
+
+`General Particle Source tutorial <https://geant4-userdoc.web.cern.ch/UsersGuides/ForApplicationDeveloper/html/GettingStarted/generalParticleSource.html>`__
+
+Add the next content (or save as a separate .mac file):
+
+.. code:: bash
+
+    
+    
+
 
 Geometry visualization
 ----------------------

docs/index.rst

@@ -37,6 +37,7 @@ ATHENA Software
    howto/beagle_generator
    howto/geometry_viewer
    howto/local_install
+   howto/geometry_to_step
 
 .. toctree::
    :maxdepth: 1

docs/overview/containers.rst

@@ -15,9 +15,9 @@ The versioning is:
 
 - **nightly** - recreated every night, using master branches
 - **testing** - recreated every night, using fixed versions
-- **3.0-stable** - the latest stable version from 3.0 branch
+- **4.0-stable** - the latest stable version from 3.0 branch
 - **unstable** (unstable-vX.x in future) - the latest build from triggered by CI from changed repo
-- **3.0.0** - exact tagged version
+- **4.0.0** - exact tagged version
 
 Nightly and testing are different in that nightly uses the master branch of the software, while testing uses whatever version is given at the top of the 
 `gitlab-ci.yml <https://eicweb.phy.anl.gov/containers/eic_container/-/blob/master/.gitlab-ci.yml#L68>`.