Self-host Lumeex and Instameex images instead of hotlinking them from git.djeex.fr

Same failure as the icon collections: img-src 'self' in the CSP silently
blocked these, they just happened to load once from browser cache before
this fix made them visibly broken.

content/en/5.nonsense/2.python/4.instameex.md

@@ -6,13 +6,13 @@ description: Instameex is a Docker-based tool to merge SDR and HDR photo exports
 
 :ellipsis{left=0px width=40rem top=10rem blur=140px zIndex=60}
 <div align="center">
-  <img src="https://git.djeex.fr/Djeex/instameex/raw/branch/main/src/assets/img/logo-long.svg" alt="Instameex Screenshot" width="300"/>
+  <img src="/img/nonsense/instameex-logo-long.svg" alt="Instameex logo" width="300"/>
 </div>
 <div align="center">
 <p>Mix your SDR and HDR exports into an Instagram-ready HDR photo.</p>
 </div>
 <div align="center">
-  <img src="https://git.djeex.fr/Djeex/instameex/raw/branch/main/illustration/instameex-illustration.png" width="640" alt="Instameex Screenshot" />
+  <img src="/img/nonsense/instameex-illustration.png" width="640" alt="Instameex illustration" />
 </div>
 ---