fix test readmes

Author: OniriCorpe

tools/readme_generator/tests/README.md

@@ -51,7 +51,7 @@ Please send your pull request to the [testing branch](https://github.com/YunoHos
 
 To try the testing branch, please proceed like that.
 
-``` bash
+```bash
 sudo yunohost app install https://github.com/YunoHost-Apps/gotosocial_ynh/tree/testing --debug
 or
 sudo yunohost app upgrade gotosocial -u https://github.com/YunoHost-Apps/gotosocial_ynh/tree/testing --debug

tools/readme_generator/tests/README_fr.md

@@ -51,7 +51,7 @@ Merci de faire vos pull request sur la [branche testing](https://github.com/Yuno
 
 Pour essayer la branche testing, procédez comme suit.
 
-``` bash
+```bash
 sudo yunohost app install https://github.com/YunoHost-Apps/gotosocial_ynh/tree/testing --debug
 ou
 sudo yunohost app upgrade gotosocial -u https://github.com/YunoHost-Apps/gotosocial_ynh/tree/testing --debug