Fix several wrong linkages

A number of changes were done to fix issues arising in the build of the user guide.

Several links were broken or not updated.

A conda environment with the required set of packages was create to help out users.

source/conf.py

@@ -14,9 +14,9 @@ author = 'NEMO System Team'
 # The short X.Y version
 version = '4.2.0'
 # The full version, including alpha/beta/rc tags
-release = 'release-4.2.0'
-
-code_repo='https://forge.nemo-ocean.eu/nemo/nemo/-/tree/' + version
+release = 'release-' + version
+# NEMO gitlab repository
+nemo_repo='https://forge.nemo-ocean.eu/nemo/nemo/-/'
 
 
 # -- General configuration ---------------------------------------------------
@@ -25,6 +25,9 @@ code_repo='https://forge.nemo-ocean.eu/nemo/nemo/-/tree/' + version
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = ['sphinx.ext.extlinks', 'sphinx.ext.todo', 'sphinxcontrib.bibtex']
+# add pip extensions
+extensions += ['sphinxext.remoteliteralinclude']
+
 bibtex_bibfiles = ['refs.bib', 'cfgs.bib', 'tests.bib']
 
 # Add any paths that contain templates here, relative to this directory.
@@ -105,9 +108,10 @@ extlinks = {
 	'github'  : ('https://github.com/NEMO-ocean/%s'         , None),
 	'xios'    : ('https://forge.ipsl.jussieu.fr/ioserver/%s', None),
 	'website' : ('https://www.nemo-ocean.eu/%s'             , None),
-	'gitlab'  : ('https://forge.nemo-ocean.eu/nemo/core'    , None),
 	'zenodo'  : ('https://zenodo.org/publication/%s'        , None),
-        'coderepo': (code_repo + '%s'                           , None),
+	'gitlab'  : (nemo_repo                                  , None),
+        'coderepo': (nemo_repo + '/tree/'+ version + '%s'       , None),
+        'tarrepo' : (nemo_repo + '/releases/'+ version + '%s'   , None),
 }
 
 # Include common directives for every rst file