Add links to readme?

[mcabbott]

As discussed here https://discourse.julialang.org/t/how-do-i-know-if-a-package-is-good/82133, it would be nice if this package's Readme linked to some alternatives: CSV.jl, DelimetedFiles.jl

I realised everyone likes to advertise what their package is good at, but sometimes users find the wrong one for their needs first. This package's name is close to Matlab's dlmread, so some people may find it who really just need the standard library's DelimetedFiles.jl.

Cc @juliohm from discourse thread.

[sl-solution]

I am ok with adding links to other packages. Please go for it. thanks.