<div>
    <p>
    Branch to be checked out in the workspace.  Default is the remote repository's default branch (typically '<code>master</code>').
    </p>
    <p>
    Note that this must be a local branch name like 'master' or 'develop' or a tag name.
    Remote branch names like 'origin/master' and 'origin/develop' are <strong>not supported</strong> as the branch argument.
    SHA-1 hashes are <strong>not supported</strong> as the branch argument.
    Remote branch names and SHA-1 hashes are supported by the general purpose <code>checkout</code> step.
    </p>
</div>

<div>
    <p>
    Branch to be checked out in the workspace.
    Default is '<code>master</code>'.
    </p>
    <p>
    Note that this must be a local branch name like 'master' or 'develop' or a tag name.
    Remote branch names like 'origin/master' and 'origin/develop' are <strong>not supported</strong> as the branch argument.
    SHA-1 hashes are <strong>not supported</strong> as the branch argument.
    Remote branch names and SHA-1 hashes are supported by the general purpose <code>checkout</code> step.
    </p>
</div>

Fix git step default branch docs
[JENKINS-64320] Fix git step default branch docs

The plugin uses a `checkout` operation rather than `clone`.  The checkout
operation is not smart enough to use the default remote branch.  Since the
`git` step is not receiving further investment, correct the documentation
to accurately describe the implmenentation.

Resolves https://issues.jenkins.io/browse/JENKINS-64320
