fix missing logos

diagram.py

@@ -13,7 +13,7 @@ trello = "./resources/trello.jpg"
 gitlab_logo = "./resources/gitlab.png"
 github_logo = "./resources/github.png"
 mailchimp = "./resources/mailchimp.png"
-nginx = "./resources/nginx.webp"
+nginx = "./resources/nginx.png"
 www = "./resources/www.png"
 instagram = "./resources/instagram.jpg"
 tiktok_logo = "./resources/tiktok.jpg"
@@ -160,7 +160,7 @@ with Diagram("BIJ1 IT landscape"):
         # what shouldn't be our cloud but currently is 😩
         gdrive = Custom("Google Drive", "./resources/google-drive.png")
 
-        mega = Custom("Mega", "./resources/mega.png")
+        mega = Custom("Mega", "./resources/mega.jpg")
 
     with Cluster("CRM"):
         civi = Custom("CiviCRM", "./resources/civicrm.jpg")
@@ -178,9 +178,8 @@ with Diagram("BIJ1 IT landscape"):
                 discords_local = Discord("Local BIJ1 Discords")
         fb_group = Facebook("Facebook groep actieve leden")
         with Cluster("Signal"):
-            signal = Custom("signal groups (many)", "./resources/signal.jpg")
+            signal = Custom("signal groups (many)", "./resources/signal.png")
 
     mollie = Custom("Mollie", "./resources/mollie.jpg")
     export_mollie = Nodejs("export-mollie")
     mollie >> export_mollie >> bij1migratie
-