Fix EU flag and KDT logo (#31)

* Adding logos and flags locally

We previously relied on an external link, which is broken now.

* Fixed EU and KDT logo links

README.md

@@ -77,8 +77,8 @@ ETISS | [ETISS](https://github.com/tum-ei-eda/etiss) | WI5.1.2 | TUM EDA | Desig
 
 TRISTAN has received funding from the Key Digital Technologies Joint Undertaking (KDT JU) under grant agreement nr. 101095947. The KDT JU receives support from the European Union’s Horizon Europe’s research and innovation programmes and participating states are Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Germany, Denmark, Estonia, Greece, Spain, Finland, France, Hungary, Ireland, Israel, Iceland, Italy, Lithuania, Luxembourg, Latvia, Malta, Netherlands, Norway, Poland, Portugal, Romania, Sweden, Slovenia, Slovakia, Turkey.
 
-![EU Logo](https://cloud.hipert.unimore.it/apps/files_sharing/publicpreview/pessWNfeqBfYi3o?x=1912&y=617&a=true&file=eu_logo.png&scalingup=0)
-![KDT Logo](https://cloud.hipert.unimore.it/apps/files_sharing/publicpreview/yd7FgKisNgtLPTy?x=1912&y=617&a=true&file=kdt_logo.png&scalingup=0) 
+![EU Logo](images/logo_EU.png)
+![KDT Logo](images/logo_KDT_JU.png)