Add script for fetching KaTeX assets

Signed-off-by: Johannes Marbach <n0-0ne+github@mailbox.org>

scripts/download-katex-assets.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+set -e
+
+root=$(git rev-parse --show-toplevel)
+
+# Check that the caller supplied a version.
+version=$1
+if [[ -z $1 || $1 = "-h" || $1 = "--help" ]]; then
+    >&2 echo "Usage: download-katex-assets.sh VERSION (e.g. v0.16.23)"
+    >&2 echo
+    >&2 echo "Downloads KaTeX fonts and CSS from the specified release"
+    >&2 echo "on GitHub and puts the files into static/."
+    exit 1
+fi
+
+# Create a temporary directory and register a handler to clean it up on exit.
+tmp_dir=$(mktemp -d)
+clean_up () {
+    rm -rf "$tmp_dir"
+} 
+trap clean_up EXIT
+
+# Fetch the release archive.
+archive=$tmp_dir/katex.tar.gz
+url=https://github.com/KaTeX/KaTeX/releases/download/$version/katex.tar.gz
+echo "GET $url"
+curl -L --output "$archive" "$url"
+
+# Unpack the archive.
+tar -xzvf "$archive" -C "$tmp_dir"
+
+# Move the CSS file into place.
+install -vm644 "$tmp_dir/katex/katex.min.css" "$root/static/css/katex.min.css"
+
+# Remove any existing fonts and move the new ones into place.
+rm -rvf "$root"/static/css/fonts/KaTeX*
+while read -r file; do
+    install -vm644 "$file" "$root/static/css/fonts"
+done < <(find "$tmp_dir/katex/fonts" -maxdepth 1 -name "KaTeX*.woff2")