Fix default make target for Netlify deployment

Change default 'all' target from 'render s3_upload' to just 'render'
since deployment is now handled by Netlify via GitHub Actions.

- 'make' or 'make all' now just builds the site
- 'make deploy' added for manual S3 upload if needed
- S3 upload is legacy, kept for backward compatibility

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: tdhopper

Makefile

@@ -3,7 +3,9 @@ OUTPUTDIR=web
 
 S3_BUCKET=pythonplot.com
 
-all: render s3_upload
+all: render
+
+deploy: render s3_upload
 
 clean:
 	rm -f Examples.*.ipynb
@@ -45,4 +47,4 @@ dev_environment: setup
 cloudfront_invalidate:
 	python .travis/invalidate_cloudfront.py
 
-.PHONY: all qrender render s3_upload run_nb travis clean cloudfront_invalidate test dev_environment setup
+.PHONY: all deploy qrender render s3_upload run_nb travis clean cloudfront_invalidate test dev_environment setup