docs: simplify readme svg (#1418)

docs/screencasts/generate-readme-svg.sh

@@ -8,6 +8,11 @@
 # screenrecordings container. A full script run takes ~20min.
 #
 
+# Create IAM configuration
+pushd constellation || exit
+constellation iam create gcp --generate-config --projectID constellation-331613 --serviceAccountID constellation-demo --zone europe-west3-b --yes
+popd || exit
+
 docker build -t screenrecodings docker
 
 # Create cast
@@ -19,14 +24,24 @@ docker run -it \
 
 # Fix meta data: width and height are always zero in Docker produced cast files.
 # Header is the first lint of cast file in JSON format, we read, fix and write it.
-head recordings/github-readme.cast -n 1 | yq e -M '.width = 95 | .height = 17' - > new_header.cast
+head -n 1 recordings/github-readme.cast | yq -M '.width = 95 | .height = 17 | . + {"idle_time_limit": 0.5}' - > new_header.cast
+# Does not work on MacOS due to a different sed
+sed -i 's/idle_time_limit:/"idle_time_limit":/' new_header.cast
 # Then append everything, expect first line from original cast file.
 tail -n+2 recordings/github-readme.cast >> new_header.cast
 
 # Then render cast into svg using:
 #   https://github.com/nbedos/termtosvg
-termtosvg render new_header.cast readme.svg -t window-frame.svg
+termtosvg render new_header.cast readme.svg -t window-frame.svg -D 1ms
 
 # Copy and cleanup
 cp readme.svg ../static/img/shell-windowframe.svg
 rm readme.svg new_header.cast
+
+# cleanup Constellation
+sudo chown -R "$USER":"$USER" ./constellation
+pushd constellation || exit
+constellation terminate -y
+constellation iam destroy -y
+rm -rf ./*
+popd || exit