docs(configuration): describe new utility "atuin-bind" for Bash

[akinomyoga]

Moved from atuinsh/docs#106. Since the PRs in atuin/docs seem to have been invalidated by atuinsh/docs#112 and #3018, let me re-create the PR here.

This is the documentation update associated with the change introduced in atuinsh/atuin#2953. The current documentation about Bash's bindings is outdated.

Checks

• I am happy for maintainers to push small adjustments to this PR, to speed up the review cycle
• I have checked that there are no existing pull requests for the same thing

[greptile-apps]

Greptile Summary

Updates Bash keybinding documentation to reflect the new atuin-bind utility introduced in version 18.10.0, replacing the outdated direct binding of __atuin_history.

• Documents the new atuin-bind function with clear syntax and special command table
• Moves old __atuin_history method to legacy section for backwards compatibility
• Clarifies version requirements for bash < 4 compatibility (no longer restricted in >= 18.10.0)
• Syntax issues from previous review have been addressed

Important Files Changed

Filename	Overview
docs/docs/configuration/key-binding.md	Documents new atuin-bind utility for Bash keybindings, replaces outdated __atuin_history documentation
docs/docs/guide/installation.md	Updates version requirement note for bash < 4 compatibility

[greptile-apps]

_{2 files reviewed, 2 comments}

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[akinomyoga]

@greptile-apps[bot] Could you check again?

[greptile-apps]

Greptile found no issues!

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[BinaryMuse]

@ellie I'm not super familiar with this, would you mind taking a look at the merge conflict

[akinomyoga]

The conflict was introduced by the merge of PR #3077, and there was no conflict when I submitted this PR four hours ago. I resolved the conflict and rebased it now.

[BinaryMuse]

Awesome, thanks for rebasing - this looks good!