Includes an explanation of how to handle updates to polyfill/lib/ecmascript.mjs from upstream
new abort and finish commands that help end rebasing prematurely, throwing away or keeping your current rebase progress respectively.
When a commit only updates the spec (no polyfill files) the tool still stopped.
This was a bug in the way calls to git rebase --continue were being handled - handling is now centralized to be consistent.
The tool will attempt to clean up the .temporal_rebase_tool folder it creates when it thinks the rebase is done.
Test262 no-op update handling might have improved - we check to see if the upstream submodule is changing before running the "handle test262 cases" logic, but I'm not 100% that will fix all the problems.
some more docs on what commands are useful during rebases
better delineation between what parts of the tool output are actually from underlying git command invocations and what parts are the tool itself.
This addresses some of the points raised in #236:
.temporal_rebase_toolfolder it creates when it thinks the rebase is done.