update --config description

src/agat/agat_sp_add_introns/config.vsh.yaml

@@ -41,7 +41,7 @@ argument_groups:
       - name: --config
         alternatives: [-c]
         description: |
-          AGAT config file. By default AGAT takes the original agat_config.yaml shipped with AGAT. The --config option gives you the possibility to use your own AGAT config file (located elsewhere or named differently).
+          AGAT config file. By default AGAT takes the original agat_config.yaml shipped with AGAT. The `--config` option gives you the possibility to use your own AGAT config file (located elsewhere or named differently).
         type: file
         required: false
         example: custom_agat_config.yaml