Add Powerline fonts installation using external repo and run_onchange script

.chezmoiexternal.toml

@@ -18,3 +18,7 @@
     type = "git-repo"
     url = "https://github.com/AstroNvim/template.git"
     refreshPeriod = "168h"
+[".powerline-fonts"]
+    type = "git-repo"
+    url = "https://github.com/powerline/fonts.git"
+    refreshPeriod = "168h"

run_onchange_install-powerline-fonts.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# Führe das install.sh Skript aus dem geklonten Repository aus
+if [ -d "$HOME/.powerline-fonts" ]; then
+    cd "$HOME/.powerline-fonts"
+    ./install.sh
+else
+    echo "Powerline Fonts Repository wurde nicht gefunden."
+fi