feat(report): add signature

report/bachelor_thesis.typ

@@ -58,7 +58,7 @@
   date: meta.date,
 
   // Declaration of honour signature
-  signature: image("figs/signature_placeholder.svg", width: 4.5cm), // A scan/photo of your handwritten signature
+  signature: image("figs/signature.png", width: 4.5cm), // A scan/photo of your handwritten signature
 
   revision: "1.0",
   code-theme: "bluloco-light",