replacemen des null , ajout surport string vide , ajout 2 command

app/src/main/java/com/iutlaval/myapplication/Game/Cards/Renaissance/Renaissance_Charles.java

@@ -33,7 +33,7 @@ public class Renaissance_Charles extends Card {
      */
     @Override
     public String getDescription() {
-        return null;
+        return "";
     }
 
     /**

app/src/main/java/com/iutlaval/myapplication/Game/Cards/Renaissance/Renaissance_Chatherine.java

@@ -33,7 +33,7 @@ public class Renaissance_Chatherine extends Card {
      */
     @Override
     public String getDescription() {
-        return null;
+        return "";
     }
 
     /**

app/src/main/java/com/iutlaval/myapplication/Game/Cards/Renaissance/Renaissance_Elisabeth.java

@@ -33,7 +33,7 @@ public class Renaissance_Elisabeth extends Card {
      */
     @Override
     public String getDescription() {
-        return null;
+        return "";
     }
 
     /**

app/src/main/java/com/iutlaval/myapplication/Game/Cards/Renaissance/Renaissance_Henri.java

@@ -33,7 +33,7 @@ public class Renaissance_Henri extends Card {
      */
     @Override
     public String getDescription() {
-        return null;
+        return "";
     }
 
     /**

app/src/main/java/com/iutlaval/myapplication/Game/Cards/Renaissance/Renaissance_Rabelais.java

@@ -34,7 +34,7 @@ public class Renaissance_Rabelais extends Card {
      */
     @Override
     public String getDescription() {
-        return null;
+        return "";
     }
 
     /**