Reorder README

Author: pubino

README.md

@@ -30,49 +30,7 @@ Multi-architecture (linux/amd64 + linux/arm64) Jupyter environment with both Pyt
 | Token control | Defaults to random, options to set a reusable token via `-e JUPYTER_TOKEN=yourtoken` or disable via `-e JUPYTER_DISABLE_TOKEN=1`|
 | Persistent user installs | Python & R packages installed in the notebook via `!pip install` / `install.packages()` persist in mounted volume |
 
-## Development 
-
-### Healthcheck
-
-Docker HEALTHCHECK runs `/usr/local/bin/healthcheck` every 2 minutes (after a 30s start period) ensuring:
-1. Python TensorFlow imports
-2. R can load Rsafd
-3. reticulate sees TensorFlow
-
-### Build Locally (Multi-Arch)
-
-```bash
-IMAGE=ghcr.io/princetonniversity/rsafd-docker:latest
-docker buildx create --name rsafd-builder --use 2>/dev/null || true
-docker buildx inspect --bootstrap
-docker buildx build --platform linux/amd64,linux/arm64 -t $IMAGE --push .
-```
-
-### GitHub Actions Workflow
-
-`.github/workflows/docker-multi-arch.yml` auto-builds on pushes to `main` and manual dispatch. Tags produced:
-* `latest`
-* Date stamp (`YYYYMMDD`)
-* Short SHA (12 chars)
-* Optional manual input tag
-
-### Runtime Smoke Tests
-
-Python:
-```python
-import tensorflow as tf, keras
-print(tf.__version__)
-```
-
-R:
-```r
-library(Rsafd)
-library(reticulate)
-py <- import('tensorflow')
-py$`__version__`
-```
-
-### Persistent Package Installs (User Space)
+## Persistent Package Installs 
 
 When you mount a host directory to `/workspace/notebooks`, the container creates a per-image hash directory that keeps any packages you install interactively:
 
@@ -112,6 +70,20 @@ To “reset” just remove the directory on the host:
 rm -rf /path/on/host/.rsafd-docker-*/
 ```
 
+## Development 
+
+### Extending
+
+Add R packages (example):
+```dockerfile
+RUN R -q -e "install.packages('xts', repos='https://cloud.r-project.org', dependencies=TRUE)"
+```
+
+Add Python packages:
+```dockerfile
+RUN /opt/venv/bin/pip install --no-cache-dir xgboost
+```
+
 ### Troubleshooting
 
 | Symptom | Cause | Fix |
@@ -121,14 +93,42 @@ rm -rf /path/on/host/.rsafd-docker-*/
 | Python cannot see newly installed pkg | Notebook kernel not restarted | Restart the kernel after `!pip install` |
 | R install asks for a CRAN mirror | Non-interactive mirror missing | Add `repos='https://cloud.r-project.org'` in `install.packages()` |
 
-### Extending
+### Healthcheck
 
-Add R packages (example):
-```dockerfile
-RUN R -q -e "install.packages('xts', repos='https://cloud.r-project.org', dependencies=TRUE)"
+Docker HEALTHCHECK runs `/usr/local/bin/healthcheck` every 2 minutes (after a 30s start period) ensuring:
+1. Python TensorFlow imports
+2. R can load Rsafd
+3. reticulate sees TensorFlow
+
+### Multi-Arch Local Build
+
+```bash
+IMAGE=ghcr.io/princetonniversity/rsafd-docker:latest
+docker buildx create --name rsafd-builder --use 2>/dev/null || true
+docker buildx inspect --bootstrap
+docker buildx build --platform linux/amd64,linux/arm64 -t $IMAGE --push .
 ```
 
-Add Python packages:
-```dockerfile
-RUN /opt/venv/bin/pip install --no-cache-dir xgboost
+### GitHub Actions Workflow
+
+`.github/workflows/docker-multi-arch.yml` auto-builds on pushes to `main` and manual dispatch. Tags produced:
+* `latest`
+* Date stamp (`YYYYMMDD`)
+* Short SHA (12 chars)
+* Optional manual input tag
+
+### Runtime Smoke Tests
+
+Python:
+```python
+import tensorflow as tf, keras
+print(tf.__version__)
+```
+
+R:
+```r
+library(Rsafd)
+library(reticulate)
+py <- import('tensorflow')
+py$`__version__`
 ```