Added zsh completion function

_msynk.compdef.zsh

@@ -0,0 +1,37 @@
+#compdef msynk
+# https://zsh.sourceforge.io/Doc/Release/Completion-System.html#Completion-Functions
+_config-file()
+{
+    # list all files in $CONFIG_DIR
+    [[ -z $XDG_CONFIG_HOME ]] && XDG_CONFIG_HOME=~/.config
+    opts=($(ls $XDG_CONFIG_HOME/msynk))
+    # -s separator, descritions options
+    _values -s , 'config files' $opts 
+}
+_msynk()
+{
+    # each argument is
+    # n:message:action
+    # option[description]:message:action
+    # *option offer multiple times
+    _arguments \
+        {--help,-h}'[We all need it at times...]' \
+        {--settings,-s}'[Show current settings.]' \
+        {--config,-c}'[Use sender, receiver, paths from config file]':config:_config-file \
+        '--show-config[Print variables defined by a config file.]':config:_config-file \
+        {--sender,-s}'[Sender directory, with trailing "/".]':directory:_directories \
+        {--receiver,-r}'[Receiver directory, with trailing "/".]':directory:_directories \
+        '--reverse[Swap receiver and sender.]' \
+        '--encrypt[Encrypt files before syncing.]' \
+        '--decrypt[Decrypt files before syncing.]' \
+        '--check-date[Only process files that have been modified since the program was last run. Needs -c and (--encrypt/--decrypt).]' \
+        '*--mkrypt-flag[Additional argument for mkrypt.]':mkrypt-flag:_mkrypt \
+        {--delete,-d}'[Delete files that exist on receiver, but not on sender. Does not work with --encrypt/--decrypt.]' \
+        '--skip-dryrun[Delete without asking first.]' \
+        '*--rsync-flag[Additional argument for rsync.]':rsync-flag:_rsync \
+        {--verbose,-v}'[Increase verbosity.]' \
+        '--silent[Decrease verbosity.]' \
+        '--debug[Maximum verbosity.]' \
+        '*:file or directory:_files'
+}
+_msynk "$@"