fix : try to fix the missing url in pkgdown config file

refs #10

_pkgdown.yml

-url: https://optirrig.pages.mia.inra.fr/optirrigBEET/
+url: ~
 template:
   package: pkgdown
   bootstrap: 5
@@ -49,3 +49,4 @@ articles:
     contents:
       - V01-Ex-Post_analysis_approach_of_Optirrig
       - V02-Sensibility_parameters_analysis
+      - V03-Study_of_the_sensitivity_of_parameters_the_case_of_sugar_beet