Link to registries at top-level docs (#788)
Link to registries at top-level docs (#788)

Add a link to the registries deployment doc in the table of contents.
quiltdata/quilt-compiler,quiltdata/quilt-compiler,quiltdata/quilt-compiler,quiltdata/quilt-compiler,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt,quiltdata/quilt