Improve internal links across documentation (#64481)

## Summary

- Adds 63 internal links across 41 documentation pages.
- Connects existing terms such as Agent Panel, semantic tokens, edit
predictions, and language-specific debugging to their detailed reference
pages.
- Uses existing wording for 60 links and makes three small wording
changes where a natural anchor did not already exist.

## Why this matters

Readers can now move from overview and configuration pages to the
relevant detailed guidance without searching the documentation manually.
The changes add navigation only. They do not change product behavior or
documented requirements.

## Jev experiment

This PR came from a local experiment using Jev to audit internal links
across the published documentation. The audit scripts are not included
in this PR.

- Code shortlisted 2,715 possible source and destination page pairs.
- Jev made two separate decisions for each pair: whether the link would
help the reader, and which exact existing phrase should become the
anchor.
- Five strong links without existing anchor text went to GPT-5.6 Luna
for minimal rewrite options. Jev then selected among those fixed
options.
- A local review interface surfaced the results for Pass or Fail
decisions before any files changed.

Human review approved 66 changes. Two no longer matched the current
`main` branch, and review removed one circular link, leaving the 63
links in this PR.

## Validation

- `pnpm dlx prettier@3.5.0 <changed docs> --check`
- `lychee --exclude '^http' './docs/src/**/*'` — 0 errors
- `mdbook build docs`
- Verified that the diff adds exactly 63 Markdown links

Release Notes:

- Improved links between related documentation pages.

docs/src/editing-code.md

@@ -20,7 +20,7 @@ Zed provides tools to help you write and modify code efficiently. This section c
 When you're editing code, Zed combines input from multiple sources:
 
 1. **Language servers** provide completions, diagnostics, and quick fixes based on your project's types and structure
-2. **Edit predictions** suggest multi-character or multi-line changes as you type
+2. **[Edit predictions](./ai/edit-prediction.md)** suggest multi-character or multi-line changes as you type
 3. **Multibuffers** let you apply changes across files in one operation
 
 For example, you might: