chore(main): release 2.0.0 (#24)

* chore(main): release 2.0.0

* docs: add 1.x->2.0 upgrade guide; fix 2.0.0 changelog migration notes

release-please generated a dangling BREAKING CHANGES note ('the options listed above ... replacements shown') because the PR-body table did not carry into the commit footer. Replace it with the real migration table and add a durable 'Upgrading from 1.x to 2.0' section to docs/tips.md (linked from README Tips & Migration).

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Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: zuqini <lizuqiliang@gmail.com>

Merge pull request #19 from zuqini/feat/keyspec-passthrough

Merge pull request #13 from zuqini/zuqini/opt-merge-refactor

refactor: collapse opts merging to single authoritative path

Merge pull request #10 from zuqini/zuqini/event-fire-missing-data

fix: forward ev.data, validate buffer, chain dependencies, and dedupl…

Merge pull request #8 from zuqini/zuqini/lazy-loading-bug

fix: lazy-loaded plugins not fully activating

docs: tighten wording in features and target audience sections

docs: add Extensions section with zshow.nvim