DOC: fixup for data package manual install
DOC: fixup for data package manual install

I'd missed out mention of the data package after the template package
install.

alexis-roche/register,alexis-roche/niseg,alexis-roche/nireg,alexis-roche/nipy,alexis-roche/nipy,arokem/nipy,alexis-roche/nipy,bthirion/nipy,arokem/nipy,alexis-roche/nipy,nipy/nireg,alexis-roche/niseg,alexis-roche/register,nipy/nireg,nipy/nipy-labs,arokem/nipy,alexis-roche/register,bthirion/nipy,nipy/nipy-labs,bthirion/nipy,alexis-roche/nireg,bthirion/nipy,arokem/nipy