Update the Czech language tag in subtitles file names.

src/api/01-basics/03-using-webvtt.md

@@ -22,7 +22,7 @@ video-subtitles:
   - default: false
     kind: captions
     label: Česky
-    src: https://storage.googleapis.com/kino-assets/using-webvtt/cap-cz.vtt
+    src: https://storage.googleapis.com/kino-assets/using-webvtt/cap-cs.vtt
     srclang: cs
 thumbnail: https://storage.googleapis.com/kino-assets/using-webvtt/thumbnail.png
 media-session-artwork:

src/api/02-streaming/04-streaming-basics.md

@@ -23,7 +23,7 @@ video-subtitles:
   - default: false
     kind: captions
     label: Česky
-    src: https://storage.googleapis.com/kino-assets/streaming-basics/cap-cz.vtt
+    src: https://storage.googleapis.com/kino-assets/streaming-basics/cap-cs.vtt
     srclang: cs
 thumbnail: https://storage.googleapis.com/kino-assets/streaming-basics/thumbnail.png
 media-session-artwork:

src/api/02-streaming/05-efficient-formats.md

@@ -23,7 +23,7 @@ video-subtitles:
   - default: false
     kind: captions
     label: Česky
-    src: https://storage.googleapis.com/kino-assets/efficient-formats/cap-cz.vtt
+    src: https://storage.googleapis.com/kino-assets/efficient-formats/cap-cs.vtt
     srclang: cs
 thumbnail: https://storage.googleapis.com/kino-assets/efficient-formats/thumbnail.png
 media-session-artwork:

src/api/02-streaming/06-adaptive-streaming.md

@@ -23,7 +23,7 @@ video-subtitles:
   - default: false
     kind: captions
     label: Česky
-    src: https://storage.googleapis.com/kino-assets/adaptive-streaming/cap-cz.vtt
+    src: https://storage.googleapis.com/kino-assets/adaptive-streaming/cap-cs.vtt
     srclang: cs
 thumbnail: https://storage.googleapis.com/kino-assets/adaptive-streaming/thumbnail.png
 media-session-artwork: