docs: 18 package repositories claim they use zsh-string-lib at install time

[ss-o]

Problem

Eighteen package repositories tell readers that the package "uses the
zsh-string-lib" to resolve its
manifest. None of them do. Zi reads package.json with .zi-parse-json in its
own lib/zsh/install.zsh, a vendored copy of @str-parse-json. Nothing in the
install path loads the library, and it is not a declared dependency anywhere.

The sentence is the same in each repository with the upstream project name
substituted, for example:

The [junegunn/fzf](https://github.com/junegunn/fzf) zsh package that uses the
[zsh-string-lib](https://github.com/z-shell/zsh-string-lib) to automatically:

It was copy-pasted at package creation; there is no template in this repository
that still generates it, so fixing a template will not fix the existing copies.

Affected repositories

• z-shell/any-gem
• z-shell/any-node
• z-shell/apr
• z-shell/asciidoctor
• z-shell/brew-completions
• z-shell/dircolors-material
• z-shell/doctoc
• z-shell/ecs-cli
• z-shell/firefox-dev
• z-shell/fzf
• z-shell/fzy
• z-shell/ls_colors
• z-shell/pyenv
• z-shell/remark
• z-shell/subversion
• z-shell/system-completions
• z-shell/zsh
• z-shell/zsh-bin

Why it matters

The claim is not merely stale, it misdirects. Someone debugging a manifest goes
and reads library source that is not the code being run, and the two copies have
already diverged: zi narrowed pair_map from ( "(" ")" "{" "}" "[" "]" ) to
( "{" "}" "[" "]" ), which is tighter for JSON. z-shell/zi#513 fixes two
further defects in the vendored copy that the library copy still has.

Change

Attribute the behavior to Zi's package support rather than to zsh-string-lib.
Where the historical relationship is worth keeping, state it as provenance, that
the parser originated in zsh-string-lib, not as a runtime dependency.

Acceptance

• No package repository claims the package uses zsh-string-lib at install
  time.
• Any retained mention is phrased as provenance.
• If package READMEs are regenerated from a shared source, that source is
  identified and corrected too, or its absence recorded.

Context

Found while reviewing z-shell/zsh-string-lib and z-shell/zsh-util-lib for
possible adoption in Zi. z-shell/zsh#20 covers the z-shell/zsh copy and is
subsumed by this issue.