v1.0.3

Documents the prebuilt install path.

The READMEs only showed dsh plugin add shinchen6/dsh-git-view, which builds
from source. The registry entry points at this release's tarball instead, so
that is the command a reader arriving through the market is actually offered.
Both READMEs now show the tarball and the source route.

No behaviour change. The asset carries the same code as v1.0.2 plus the
updated READMEs.