Update documentation on how to override the delimiter_var configuration

Signed-off-by: alexis-opolka <alexis.opolka@proton.me>

docs/navi_config.md

@@ -104,9 +104,20 @@ You can define it as such:
 
 ```yaml
 finder:
-  delimiter_var: <your-regex-delimiter>
+  delimiter_var: <your-regex-delimiter> ### By default the expression is \s\s
 ```
 
 > [!CAUTION]
 > Defining the delimiter via the configuration file means that Navi will use this delimiter by default for
 > every variable using the `--column` instruction.
+
+You can override this configuration with the `--delimiter` instruction in the variable definition of your cheatsheet.
+
+It can be overriden like this:
+
+```yaml
+echo <image_id>
+
+$ image_id: ... --- --column 3 --header-lines 1 --delimiter '\s\s+' # <-- This variable uses \s\s+ as a delimiter
+$ image_tag: ... --- --column 3 --header-lines 1 # <-- This variable uses the default delimiter
+```