[BERLIN-2026] push fixes from comments

Author: range

static/events/2026-berlin/logo-square.jpg assets/events/2026-berlin/logo-square.jpgstatic/events/2026-berlin/logo-square.jpg renamed to assets/events/2026-berlin/logo-square.jpg

@@ -5,7 +5,7 @@ event_twitter: "blndevops" # Change this to the twitter handle for your event su
 description: "Devopsdays is coming back to Berlin!" # Edit this to suit your preferences
 ga_tracking_id: "" # If you have your own Google Analytics tracking ID, enter it here. Example: "UA-74738648-1"
 
-event_logo: "logo-square.jpg"
+event_logo: "logo-square.png"
 # sharing_image: "2022-sharing-logo-berlin.png"
 masthead_background: "berlin-masthead.png"
 
@@ -105,8 +105,6 @@ organizer_email: "[email protected]" # Put your organizer email address here
 # List all of your sponsors here along with what level of sponsorship they have.
 # Check data/sponsors/ to use sponsors already added by others.
 sponsors:
-  - id: samplesponsorname
-    level: gold
  #  url: http://mysponsor.com/?campaign=me # Use this if you need to over-ride a sponsor URL.
   - id: arresteddevops
     level: community