docs: v18 announcement tweaks

[markwhitfeld]

This PR makes some modifications to the v18 announcement post, ahead of publication.

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The commit message follows our guidelines: https://github.com/ngxs/store/blob/master/CONTRIBUTING.md#commit
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[x] Documentation content changes
[ ] Other... Please describe:

[nx-cloud[bot]]

☁️ Nx Cloud Report

CI is running/has finished running commands for commit 12f1131c3eed4302c68c4f5acf140fdc00f19d84. As they complete they will appear below. Click to see the status, the terminal output, and the build insights.

📂 See all runs for this CI Pipeline Execution

---

✅ Successfully ran 4 targets

- [`nx run-many --target=test --all --configuration=ci --maxWorkers=4`](https://cloud.nx.app/runs/5oCUxTXz2U?utm_source=pull-request&utm_medium=comment) - [`nx run-many --target=lint --all`](https://cloud.nx.app/runs/6XIlj4pKk1?utm_source=pull-request&utm_medium=comment) - [`nx lint-types store`](https://cloud.nx.app/runs/vLY9ihnrak?utm_source=pull-request&utm_medium=comment) - [`nx run-many --target=build --all`](https://cloud.nx.app/runs/yUWHHO6nuw?utm_source=pull-request&utm_medium=comment)

---

Sent with 💌 from NxCloud.

[bundlemon[bot]]

BundleMon (Integration Projects)

Unchanged files (2)

Status | Path | Size | Limits :------------: | ------------ | :------------: | :------------: :white_check_mark: | Main bundles(Gzip)
_{hello-world-ng17/dist-integration/main.(hash)
.js}
| 69.46KB | +1% :white_check_mark: | Main bundles(Gzip)
_{hello-world-ng16/dist-integration/main.(hash)
.js}
| 68.47KB | +1%

No change in files bundle size

Final result: :white_check_mark:

View report in BundleMon website ➡️

---

Current branch size history | Target branch size history

[msmallest]

Will the root README.md be updated when this post is released, in a different PR?

I ask because having the root GitHub README.md differ from the docs one and NPM one, as well as v18 being released, has been a point of confusion for me about the formal status of the release and the messaging about it.

I know I can use v18 now, but I could see this being a point of confusion.

BTW nice release, good changes.

[codeclimate[bot]]

Code Climate has analyzed commit 12f1131c and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 95.4% (0.0% change).

View more on Code Climate.