A small patch release adding the nub x spelling and correcting the run-a-package docs.

nub x — a short alias of dlx

nub x <pkg> now fetches and runs a package, identical to nub dlx <pkg> and nubx <pkg>. The existing nub dlx, nub exec, and nubx entrypoints are unchanged. The docs now describe the three fetch-and-run spellings — nubx, nub dlx, and nub x — and the local-bin runner, nub exec, accurately.

[!NOTE] nub dlx and nub exec already shipped in 0.2.4. This release adds the x spelling and corrects the documentation; it does not change the behavior of dlx, exec, or nubx.

The full release notes list every change in this release.