MT#57728 docs: add a packaging guide

A packaging guide is introduced.

Change-Id: I553df94ef00234e6aa451c779b402f7fa20cbdf8

docs/index.rst

@@ -18,3 +18,4 @@ Welcome to the SEMS Project Documentation
 
    Usage <usage>
    Compilation and installation <installation>
+   Packaging <packaging>

docs/packaging.md

@@ -0,0 +1,89 @@
+# Packaging
+
+This is an alternative to manual compilation of SEMS from sources.
+
+SEMS project provides a possibility to build packages for further installation on systems (e.g. debian OS)
+based on given sources in repository.
+This guide gives short and simple explanation how to quickly prepare SEMS packages for usage.
+
+## Clone
+
+First of all get the latest version of SEMS from the GH repository with the command:
+```
+git clone https://github.com/sipwise/sems.git
+```
+
+_If you still don't have git tool in your environment, just install `git` package from an official repository of your distribution._
+
+Now, it may happen there is a need for specific version of SEMS, like those LTS versions project provides.
+For that to work run the following command being in the directory of cloned repository:
+```
+git checkout --track origin/<version>
+```
+
+Example:
+```
+git checkout --track origin/mr13.2.1
+```
+
+_Tips and tricks: it may happen you have an older version of repository locally, and hence you lack certain newer versions, to fix that just run `git fetch origin`._
+
+## Built packages with sbuild
+
+Install sbuild developers environment and pristine:
+```
+apt install sbuild-debian-developer-setup pristine-tar
+```
+
+Configure and start sbuild environment (for that you might will need sudo permissions):
+```
+sbuild-debian-developer-setup --suite=bookworm
+```
+
+_In this example as a suite the bookworm distro is selected_
+
+Previously run command should add your user into sbuild and will add some required directories.
+After that is done, run the following command:
+```
+newgrp sbuild
+```
+
+Now the future package is to be built in a proper suite:
+```
+gbp buildpackage --git-builder=sbuild \
+--git-debian-branch=master -d bookworm --no-clean-source 
+```
+
+_In this example we build master version of SEMS for the debian bookworm distribution._
+
+## Missing dependencies
+
+Sometimes one has to deal with missing dependencies:
+```
+The following packages have unmet dependencies:                                                          
+ sbuild-build-depends-main-dummy : Depends: portaudio19-dev but it is not going to be installed          
+                                   Depends: systemd-dev but it is not installable
+E: Unable to correct problems, you have held broken packages.
+apt-get failed.                                    
+E: Package installation failed         
+```
+
+To fix that just install required packages (e.g. `portaudio19-dev`, `systemd-dev` or alike) from the official repository of your distribution.
+
+## Results
+
+Now in the ../ directory there should be a list of files created like:
+```
+ngcp-sems_1.6.0+0~mr13.3.0.0_amd64.deb
+ngcp-sems-dbgsym_1.6.0+0~mr13.3.0.0_amd64.deb
+ngcp-sems_1.6.0+0~mr13.3.0.0.tar.xz
+ngcp-sems_1.6.0+0~mr13.3.0.0_amd64-2025-03-01T20:45:27Z.build
+ngcp-sems_1.6.0+0~mr13.3.0.0_amd64.build -> ngcp-sems_1.6.0+0~mr13.3.0.0_amd64-2025-03-01T20:45:27Z.build
+ngcp-sems_1.6.0+0~mr13.3.0.0_amd64.buildinfo
+ngcp-sems_1.6.0+0~mr13.3.0.0_amd64.changes
+ngcp-sems_1.6.0+0~mr13.3.0.0.dsc
+```
+
+From those only .deb packages will be required to deploy SEMS binaries on the wished system,
+so the `ngcp-sems_<version>` and `ngcp-sems-dbgsym_<version>` one. Whereas dbgsym isn't really required
+for a normal run of this binary, but is only needed for a future coredump investigation using gdb.