Update README.md with v8 alpha announcement

[joelhulen]

The issue or feature being addressed

Details on the issue fix or feature implementation

Confirm the following

• I started this PR by branching from the head of the default branch
• I have targeted the PR to merge into the default branch
• I have included unit tests for the issue/feature
• I have successfully run a local build

[codecov]

Codecov Report

Merging #1317 (809ee39) into main (488bc10) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1317   +/-   ##
=======================================
  Coverage   83.29%   83.29%           
=======================================
  Files         264      264           
  Lines        6305     6305           
  Branches      997      997           
=======================================
  Hits         5252     5252           
  Misses        844      844           
  Partials      209      209           

Flag	Coverage Δ
macos	83.29% <ø> (ø)
windows	?

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