Revise wiki to add custom command for AI Generated Commits using `cfme`

[codevogel]

I have updated the wiki in my manual fork here, to add a Custom Command that showcases how to add AI generated commits as a feature to lazygit.

I have conveniently placed it under the 'commit with commitizen' section, as that is the first mention of 'commit' and committing with Commit For Me is is quite related to Commitizen, as they both offer the convential-commits standard as the default

Here's an example of the proposed changes:

## committing via [Commitizen](https://commitizen-tools.github.io/commitizen/) (`cz c`)

<truncated content>

## Generating commit messages with AI via [Commit For Me](https://github.com/codevogel/commit-for-me)

\```yml
customCommands:
  - key: "<c-a>"
    description: "generate message candidates and commit using cfme"
    command: "cfme"
    context: "files"
    loadingText: "Generating commit message with cfme..."
    subprocess: true
\```

## Searching the repo's history for a word appearing in a specified subtree

Mind the \ since otherwise the GitHub formatting breaks in this issue.

The custom command is listed here for easy copying: https://github.com/codevogel/commit-for-me/?tab=readme-ov-file#lazygit