build: add useful scripts for installing template

Can now install it locally (or anywhere else) quite easily. This is the first step for being able to auto create PRs when we do a release

scripts/package

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+set -eu
+
+# adapted from https://github.com/johannes-wolf/cetz/blob/35c0868378cea5ad323cc0d9c2f76de8ed9ba5bd/scripts/package
+# licensed under Apache License 2.0
+
+. "$(dirname "${BASH_SOURCE[0]}")/setup"
+
+if (( $# < 1 )) || [[ "${1:-}" == "help" ]]; then
+  echo "package TARGET"
+  echo ""
+  echo "Packages all relevant files into a directory named '<name>/<version>'"
+  echo "at TARGET. If TARGET is set to @local or @preview, the local Typst package"
+  echo "directory will be used so that the package gets installed for local use."
+  echo "The name and version are read from 'typst.toml' in the project root."
+  echo ""
+  echo "Local package prefix: $DATA_DIR/typst/package/local"
+  echo "Local preview package prefix: $DATA_DIR/typst/package/preview"
+  exit 1
+fi
+
+TARGET="$(resolve-target "${1:?Missing target path, @local or @preview}")"
+echo "Install dir: $TARGET"
+
+# ignore rules
+readarray -t ignores < <(grep -v '^#' .typstignore | grep '[^[:blank:]]')
+
+# recursively print all files that are not excluded via .typstignore
+function enumerate {
+	local root="$1"
+	if [[ -f "$root" ]]; then
+		echo "$root"
+	else
+		local files
+		readarray -t files < <(find "$root" \
+      -mindepth 1 -maxdepth 1 \
+      -not -name .git \
+      -not -name .typstignore)
+		# declare -p files >&2
+
+		local f
+		for f in "${files[@]}"; do
+			local include
+			include=1
+
+			local ignore
+			for ignore in "${ignores[@]}"; do
+				if [[ "$ignore" =~ ^! ]]; then
+					ignore="${ignore:1}"
+					if [[ "$f" == ./$ignore ]]; then
+						# echo "\"$f\" matched \"!$ignore\"" >&2
+						include=1
+					fi
+				elif [[ "$f" == ./$ignore ]]; then
+					# echo "\"$f\" matched \"$ignore\"" >&2
+					include=0
+				fi
+			done
+			if [[ "$include" == 1 ]]; then
+				enumerate "$f"
+			fi
+		done
+	fi
+}
+
+# List of all files that get packaged
+readarray -t files < <(enumerate ".")
+# declare -p files >&2
+
+TMP="$(mktemp -d)"
+
+for f in "${files[@]}"; do
+  mkdir -p "$TMP/$(dirname "$f")" 2>/dev/null
+  cp -r "$ROOT/$f" "$TMP/$f"
+done
+
+TARGET="${TARGET:?}/${PKG_PREFIX:?}/${VERSION:?}"
+echo "Packaged to: $TARGET"
+if rm -r "${TARGET:?}" 2>/dev/null; then
+  echo "Overwriting existing version."
+fi
+mkdir -p "$TARGET"
+
+# include hidden files by setting dotglob
+shopt -s dotglob
+mv "$TMP"/* "$TARGET"