Add new members to Engine and Cmdlet Working Groups (and typo fix)

[joeyaiello]

PR Summary

As discussed by @PowerShell/powershell-committee, we're happy to welcome new community members to our Engine and Cmdlet Working Groups (the latter of which we recently decided to instantiate to manage those modules that live within PowerShell/PowerShell).

We're pleased to bring both @vexx32 and @rkeithhill onboard to the Engine WG, as well as @TobiasPSP and @jdhitsolutions to the Cmdlet WG.

To move forward, we should probably get a final Committee-Approved label (as a formality) /cc @SteveL-MSFT

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Make sure all .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: or [ WIP ] to the beginning of the title (the WIP bot will keep its status check at Pending while the prefix is present) and remove the prefix when the PR is ready.
• Breaking changes
  • None
  • OR
  • Experimental feature(s) needed
    • Experimental feature name(s):
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed
    • Issue filed:
• Testing - New and feature
  • N/A or can only be tested interactively
  • OR
  • Make sure you've added a new test if existing tests do not effectively test the code changed
• Tooling
  • I have considered the user experience from a tooling perspective and don't believe tooling will be impacted.
  • OR
  • I have considered the user experience from a tooling perspective and opened an issue in the relevant tool repository. This may include:
    • Impact on PowerShell Editor Services which is used in the PowerShell extension for VSCode
      (which runs in a different PS Host).
      • Issue filed:
    • Impact on Completions (both in the console and in editors) - one of PowerShell's most powerful features.
      • Issue filed:
    • Impact on PSScriptAnalyzer (which provides linting & formatting in the editor extensions).
      • Issue filed:
    • Impact on EditorSyntax (which provides syntax highlighting with in VSCode, GitHub, and many other editors).
      • Issue filed:

[daxian-dbw]

/bin/bash --noprofile --norc /home/vsts/work/_temp/55508924-6b9e-4fb5-9ebd-2a4d95d6b426.sh
    docs/community/working-group-definitions.md
      139 | * @TobiasPSP 
      140 | * @jdhitsolutions 

>> 2 spelling errors found in 76 files

@joeyaiello The spelling checks failed in CI. You will have to update the .spelling file. You can run mdspell '**/*.md' '!**/Pester/**/*.md' '!**/perf/**/*.md' --ignore-numbers --ignore-acronyms --en-us and choose "add to ignore file" as a spelling issue is spotted, or you can manually update .spelling.

[ghost]

🎉v7.2.0-preview.7 has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes