add compression to autocomplete

Signed-off-by: Zen <[email protected]>

Author: desultory

completion/_pycpio

@@ -24,6 +24,8 @@ args=("-i[input archive]:archive:_files"
       "--set-group[GID]:GID:_groups"
       "-m[file mode]:mode"
       "--set-mode[file modes]:mode"
+      "-z[compression]:compression:(xz)"
+      "--compress[compression]:compression:(xz)"
       "-o[output archive]:archive:_files"
       "--output[output archive]:archive:_files"
       "--log-file[specify the log file]:log file:_files"