README: add Windows / WSL2 note for ddev contributors

README.md

@@ -61,6 +61,16 @@ rm -f app/data.db app/data.db-shm app/data.db-wal
 rm -rf app/uploads
 ```
 
+### Windows
+
+DDEV runs on Windows via WSL2 — install WSL2 + an Ubuntu distro, then
+follow the Linux install instructions *inside* WSL:
+<https://ddev.readthedocs.io/en/stable/users/install/ddev-installation/#windows>.
+
+Keep the repo on the WSL filesystem (`~/projects/cms-plugins` inside
+Ubuntu), not under `/mnt/c/…` — Vite HMR and `npm install` are
+noticeably slower across the Windows ↔ Linux mount boundary.
+
 ## Deploying
 
 Push to the matching branch: