Minor Documentation Changes

[plun1331]

Summary

• Fixes a problem with syntax:
  

• Edits the installation guide to mention the pre-release on PyPi instead of installing from git.

  • Also removes the outdated release date

• Fixes other typing/spelling errors

• Updates information on the message content intent

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, typehinting, examples, ...)

[plun1331]

A note could also be used for mentioning the pre-release, instead of some !!! IMPORTANT !!! text.