add __enter__ and __exit__ to PdfPages
multipage pdf: show usage of with statement in example
Remove dead RMS computation code
Merge pull request #2426 from mdboom/testing/remove-dead-rms-computation

Remove dead rms computation
Merge pull request #2319 from tacaswell/draw_idle_fix

fix draw_idle reference in  NavigationToolbar2
Add webagg api docs
only show preferred usage of PdfPages in examples
show only preferred usage for PdfPages and use preferred pyplot import
style
Merge pull request #2271 from mdboom/add-webagg-docs

docs: add webagg-backend
Merge pull request #2416 from megies/multipage_pdf_with_statement

Multipage pdf with statement
Merge remote-tracking branch 'upstream/v1.3.x'