Add build timeline method

[alanrmatthews]

Add new method to get the build timeline for a given build.

Also explicitly defined the formatter as "black" in the VS Code settings.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 20.00000% with 4 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@2f342b7). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
simple_ado/builds.py	20.00%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #53   +/-   ##
=======================================
  Coverage        ?   49.35%           
=======================================
  Files           ?       34           
  Lines           ?     2099           
  Branches        ?        0           
=======================================
  Hits            ?     1036           
  Misses          ?     1063           
  Partials        ?        0           

Flag	Coverage Δ
unittests	49.35% <20.00%> (?)

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[alanrmatthews]

I guess I don't have permissions to complete PRs