docs: apply writing guidelines across the docs site

[roziscoding]

Applies the writing conventions from the global CLAUDE.md to every docs page except guide/quick-links.md, which was already written to them in #86.

No behavioural or factual changes, prose only.

What changed

• Em dashes used as pauses or pivots replaced with commas, colons, semicolons, or a second sentence (the bulk of the diff, ~60 instances).
• Bullet label separators normalised from - **Label** — text to - **Label**: text.
• UI references are now bold+italic with ASCII arrows: ***Settings -> Downloads***, ***Settings -> General -> API Key***, ***Live*** / ***Reconnecting...***.
• Rule-of-three phrasing removed: the index hero tagline, the what-is-jack intro, and the unlink description in troubleshooting.
• Counting before a list dropped: "three usual causes" and "two on-disk outcomes" now just introduce their lists.
• Preamble and filler cut: "First, a decoding tip:", "That's it —".
• Wh-word heading renamed: 3. Serving — being a peer to others -> 3. Serving as a peer to others.
• Unicode punctuation (—, →, …, smart quotes) removed from prose, including the mounts table in getting-started.

Not changed

• Mermaid blocks in how-it-works.md keep → and … inside message labels, since -> there collides with mermaid's own arrow syntax.
• [operationId].paths.ts keeps the em dash in its generated page titles, where it separates title from section rather than acting as a pause.

Renamed headings keep their existing anchors (verified in the built HTML), and bun run build passes.

[greptile-apps]

Greptile Summary

The PR applies the repository’s writing conventions across the documentation without changing application behavior.

• Replaces Unicode punctuation and em-dash constructions with the prescribed ASCII punctuation and sentence structures.
• Standardizes UI references, list labels, headings, and concise phrasing.
• Adds the writing conventions to AGENTS.md.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

_{Reviews (2): Last reviewed commit: "docs: add writing guidelines to AGENTS.m..." | Re-trigger Greptile}