docs: Add section about containers

[skip ci]

docs/index.md

@@ -175,6 +175,33 @@ Assuming the default STAR environment on a RACF interactive node the code can be
 compiled as usual with the `cons` command.
 
 
+## Containers
+
+Containers are useful for many reasons. In particular, they can be used to
+eliminate the necessity to worry about the software infrastructure for the
+developers and users while allowing to run their application on different
+operating systems and platforms.
+
+It is possible to recreate the environment that includes all dependencies
+required to compile the STAR libraries by using the [`star-sw` Docker
+images](https://github.com/star-bnl/star-sw/pkgs/container/star-sw). These
+images are automatically updated on every successful merge into the main branch
+and for every tagged release.
+
+If `singularity` is installed on your system and, for example, you want to work
+with the STAR libraries built against ROOT5 using GCC 4.8.5 run the following
+command:
+
+```shell
+singularity run docker://ghcr.io/star-bnl/star-sw:main-root5-gcc485 bash -l
+```
+
+It may take some time to download the image and instantiate a singularity
+container but once completed you should see a shell prompt from where you can
+browse your local files. At this point you should be able to compile and test
+modifications made to a package in `StRoot/` by running `cons` as usual.
+
+
 ## Contributing to the STAR software library
 
 ### Common workflow