Document blog runtime tmpfs

Author: AnastaZIuk

README.md

@@ -63,3 +63,4 @@ The Graphics Programming Blog - A collection of technical articles, project post
 - Build: `npm run build` produces the `build/` directory.
 - Final container copies only `build/` plus the Caddy service binary; there is no Node/npm runtime remaining, everything is pre-rendered.
 - Run in production with `--read-only` and `tmpfs` (e.g. `/tmp:size=32m`, `/config:size=32m`, `/data:size=32m`) so Caddy can keep its cache/autosave files while leaving the image immutable.
+> ⚠️ These warnings mirror the main website: the blog image never contains Node/npm at runtime, and the tmpfs mounts keep minimal metadata writable without compromising the read-only root filesystem.