Use vitejs instead of react-scripts

- react-scripts are not maintained anymore
- vitejs is well suited for single page applications

Fixes #335

See https://darekkay.com/blog/create-react-app-to-vite/

Change-Id: Ib884748e373094a640b576894ff67b98c3584ec8

README.md

@@ -79,8 +79,6 @@ You have three options:
         context: https://github.com/Awesome-Technologies/synapse-admin.git
         # args:
         #   - NODE_OPTIONS="--max_old_space_size=1024"
-        #   # see #266, PUBLIC_URL must be without surrounding quotation marks
-        #   - PUBLIC_URL=/synapse-admin
       ports:
         - "8080:80"
       restart: unless-stopped
@@ -122,6 +120,40 @@ services:
     ...
 ```
 
+### Serving Synapse-Admin on a different path
+
+We do not support directly changing the path where Synapse-Admin is served. Instead please use a reverse proxy if you need to move Synapse-Admin to a different base path. If you want to serve multiple applications with different paths on the same domain, you need a reverse proxy anyway.
+
+Example for Traefik:
+
+`docker-compose.yml`
+
+```yml
+services:
+  traefik:
+    image: traefik:mimolette
+    restart: unless-stopped
+    ports:
+      - 80:80
+      - 443:443
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+    labels:
+      - "traefik.http.middlewares.admin.redirectregex.regex:^(.*)/admin/?"
+      - "traefik.http.middlewares.admin.redirectregex.replacement:$${1}/admin/"
+      - "traefik.http.middlewares.admin_path.replacepathregex.regex:^/admin/(.*)"
+      - "traefik.http.middlewares.admin_path.replacepathregex.replacement:/$1"
+
+  synapse-admin:
+    image: awesometechnologies/synapse-admin:latest
+    restart: unless-stopped
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.synapse-admin.priority=3"
+      - "traefik.http.routers.synapse-admin.rule=Host(`example.com`)&&PathPrefix(`/admin`)"
+      - "traefik.http.routers.synapse-admin.middlewares=admin,admin_path"
+```
+
 ## Screenshots
 
 ![Screenshots](./screenshots.jpg)