Repo improvements

[markreidvfx]

This pull request address the following the tasks in #1

• Add Code of Conduct and Contributing docs (matching unreal plugins style)
• Fix Badge path in Readme
• Add issue and pull request templates
• Fix CI pip install OTIO URL
• Add CodeCov CI support
• Add Dependabot
• Small Readme improvements

CodeCov/Dependabot might need to be enabled on the repo settings if it's not already.

[codecov-commenter]

Codecov Report

:exclamation: No coverage uploaded for pull request base (main@46f749e). Click here to learn what that means. The diff coverage is n/a.

@@           Coverage Diff           @@
##             main       #2   +/-   ##
=======================================
  Coverage        ?   90.03%           
=======================================
  Files           ?        3           
  Lines           ?     1114           
  Branches        ?        0           
=======================================
  Hits            ?     1003           
  Misses          ?      111           
  Partials        ?        0           

Flag	Coverage Δ
unittests	90.03% <0.00%> (?)

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[markreidvfx]

Added the requested changes to the pull. Everything should be addressed unless I missed something :p