Fix typos and broken links in docs, changelogs and build config

[olitreadwell]

What changed

Fix several typos and two broken links across the docs, changelogs and build config.

• thats becomes that's in the drift file API docs.
• Encode the parentheses in the Wikipedia "Window function" link so it resolves (it currently 404s).
• Point the "older version of Electric SQL" note at the live electric-sql.com URL, since the legacy subdomain no longer serves the site.
• Fix compatiblity in the drift changelog and whereever, unecessary, correclty in the drift_dev changelog.
• Fix unecessary in the sqlparser changelog.
• Fix Exlude to Exclude in the drift build and test configs.

Why

All changes are meaning-preserving trivial fixes from a cleanup pass over the repo.
The Wikipedia link genuinely 404s because its closing parenthesis is missing, and the legacy.electric-sql.com link no longer loads.
The other changes are plain misspellings in user-facing docs, changelogs and build-config comments.

How to verify

git fetch https://github.com/olitreadwell/drift.git docs/fix-more-doc-typos
git checkout FETCH_HEAD
dart format -o none --set-exit-if-changed .
dart analyze --fatal-infos --fatal-warnings
dart test

[simolus3]

Thanks!

[simolus3]

The link as rendered on the website works for me.

[simolus3]

Even the new ElectricSQL is kind of dead at this point, so we should probably just remove the entire section.

[simolus3]

Merged in 00d2f2e, thanks!