Old Link Address for Public Use Linked Mortality Files

[nmshahir]

The link associated with Public-Use Linked Mortality Files on https://www.kylegrealis.com/nhanesdata/articles/the-datasets.html seems to be old.
It currently redirects to https://www.cdc.gov/nchs/linked-data/mortality-files/ but it might be good to update it.

[jarbet]

I also recommend adding the mortality dataset to the searchable table in this vignette

I was trying to figure out of nhanesdata contains the mortality data or not, and I didn't find my answer until finding this issue. Glad to see the mortality data is included though!