DOC: Double backticks in lagfit. (#21948)
DOC: Double backticks in lagfit. (#21948)

Some of the values in the documentation of lagfit are in single-backticks,
though single backticks usually means that this is a reference to
something else that sphinx tries to resolve. Here I update values that
reference nothing to use double backticks (verbatim), or emphasis.
numpy/numpy,endolith/numpy,mhvk/numpy,mhvk/numpy,rgommers/numpy,rgommers/numpy,rgommers/numpy,charris/numpy,numpy/numpy,charris/numpy,mattip/numpy,anntzer/numpy,rgommers/numpy,endolith/numpy,anntzer/numpy,endolith/numpy,mhvk/numpy,mhvk/numpy,mattip/numpy,charris/numpy,mattip/numpy,mhvk/numpy,numpy/numpy,numpy/numpy,endolith/numpy,charris/numpy,anntzer/numpy,mattip/numpy,anntzer/numpy