chore: init unit tests

[mackenzie-grimes-noaa]

Checklist

• Version number incremented in package.json

Changes

• Add vitest unit testing framework, and a very simple unit test.

Explanation

Unit test coverage is a meek 14.6%, but it's a start. Future work may update the unit test coverage report in the README.md

------------------------|---------|----------|---------|---------|-----------------------
File                    | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s     
------------------------|---------|----------|---------|---------|-----------------------
All files               |    14.6 |    42.85 |   26.66 |    14.6 |                       
 muppet                 |       0 |        0 |       0 |       0 |                       
  index.js              |       0 |        0 |       0 |       0 | 1-6                   
 muppet/src             |   15.56 |       60 |   36.36 |   15.56 |                       
  MuppetChannel.js      |       0 |        0 |       0 |       0 | 1-415                 
  MuppetProvider.jsx    |       0 |        0 |       0 |       0 | 1-86                  
  session.js            |   69.62 |       75 |      80 |   69.62 | 22-25,43-46,72-87     
  utils.js              |   55.55 |      100 |       0 |   55.55 | 5-6,17-23,31-38,51-57 
 muppet/src/hooks       |       0 |        0 |       0 |       0 |                       
  useMuppetCallback.jsx |       0 |        0 |       0 |       0 | 1-57                  
  useMuppetChannel.jsx  |       0 |        0 |       0 |       0 | 1-21                  
  useMuppetChannels.jsx |       0 |        0 |       0 |       0 | 1-19                  
------------------------|---------|----------|---------|---------|-----------------------