Mention training sessions, joining the effort, and guix-hpc@gnu.org.

* about.md: Mention joining and guix-hpc@gnu.org.
* posts/guix-hpc-debuts.md: Likewise, and mention training sessions.

about.md

@@ -6,4 +6,9 @@ Guix-HPC is a joint software development project between
 [Max Delbrück Center for Molecular Medicine (MDC)](https://www.mdc-berlin.de/),
 and [UMC Utrecht](http://www.umcutrecht.nl/en/-1).  Guix-HPC an effort
 to optimize [GNU Guix](https://gnu.org/s/guix) for reproducible
-scientific workflows in high-performance computing (HPC).
+scientific workflows in high-performance computing (HPC).  See our
+[introductory article](/news/guix-hpc-debut.html) for an overview.
+
+If you are using Guix in an HPC context at your workplace, or if you
+would like to find ways to address your own HPC use cases, please
+consider joining us!  Email us at `guix-hpc@gnu.org`.

posts/guix-hpc-debuts.md

@@ -186,8 +186,9 @@ The other reason is the fact that, to achieve build isolation,
 usually only available to system administrators.
 
 The Guix-HPC effort will attempt to address this, both through technical
-means (more on that later) and by discussing and raising awareness of
-the reproducibility and deployment situation in the HPC community.  We
+means (more on that later), by discussing and raising awareness of
+the reproducibility and deployment situation in the HPC community, and
+by giving talks and running training sessions.  We
 will also work on improving the user experience and workflows for
 researchers using Guix with HPC and reproducibility in mind.
 
@@ -197,3 +198,6 @@ We’ll also describe concrete actions we’ve identified to achieve these
 goals.  So please stay tuned, and share your ideas, comments, and
 criticism with us on the
 [`guix-devel` mailing list](https://www.gnu.org/software/guix/about/#contact)!
+If you are already using Guix and would like to join the effort, or if
+you have questions about training sessions or deployment on your
+cluster, please email us on the `guix-hpc@gnu.org` private alias.