add excalidraw backend (for jitsi whiteboard)

conf.d/excalidraw-backend.conf

@@ -0,0 +1,21 @@
+server {
+	listen 443 ssl http2;
+	listen [::]:443 ssl http2;
+	server_name ed-back.vern.cc;
+	include snippets/lets-encrypt.conf;
+
+	location / {
+		proxy_pass http://localhost:5069/;
+		proxy_redirect off;
+		proxy_set_header Host $host;
+		proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+		proxy_set_header X-Forwarded-Proto $scheme;
+		proxy_cookie_path / "/; Secure; HttpOnly; SameSite=lax";
+	}
+}
+server {
+	listen 80;
+	listen [::]:80;
+	server_name ed-back.vern.cc;
+	return 301 https://$host$request_uri;
+}