try to get images to show up in gitea

cert_instructions/ios_cert.md

@@ -5,7 +5,7 @@
  * You should now see a list of your devices. Find your iOS device and tap the "iOS" link to download the certificate.
  * After tapping on the "iOS" link you should see a popup asking you to confirm, as in the screenshot below
 
-<img src="ios_screenshots/01_download_profile.png" alt="screenshot of download profile popup" height="500"/>
+ <img src="ios_screenshots/01_download_profile.png" alt="[screenshot of download profile popup](ios_screenshots/01_download_profile.png)" height="500"/>
  
  * Tap "Allow" to download the profile
  * You should now see a pop-up titled "Profile Downloaded" as in the screenshot below. Tap the Close button on this pop-up.