Options and posargs titles appear corrupted (sometimes?)

[webknjaz]

pypa/build uses this extension with :title: python -m build and the first title shows up correctly as python -m build but the following ones are python -m positional arguments and python -m options with the build segment lost.

See: https://pypa-build.readthedocs.io/en/stable/#python--m-build-options.

[gaborbernat]

PR welcome 👍