doc: add module cmd enabling guidelines for Csh

Signed-off-by: Xavier Delaruelle <[email protected]>

Author: xdelaruelle

.hunspell.en.dic

@@ -1222,3 +1222,5 @@ LMUSE
 EESSI
 shopt
 fi
+loginsh
+endif

INSTALL.rst

@@ -185,15 +185,29 @@ running a script. Add the following code snippets to the initialization files
 of the shell you use.
 
 * For **Bash**, update either system-wide (``/etc/bash.bashrc`` on Debian-like
-  systems) or personal (``~/.bashrc``) initialization file
+  systems) or personal (``~/.bashrc``) initialization file:
 
   .. code-block:: sh
 
-      # enable module command in non-interactive shells
+      # enable module command in non-login shells
       if ! shopt -q login_shell; then
           . /usr/share/modules/init/bash
       fi
 
+* For **Csh**/**Tcsh**, add Modules initialization file into Csh rc directory
+  (``/etc/csh/cshrc.d`` on Debian-like systems)::
+
+      ln -s /usr/share/modules/init/csh /etc/csh/cshrc.d/modules
+
+  Or update personal (``~/.cshrc``) initialization file:
+
+  .. code-block:: csh
+
+      # enable module command in non-login shells
+      if (! $?loginsh) then
+          source /usr/share/modules/init/csh
+      endif
+
 Configuration
 -------------