Fix style issues in the changelog  [ci skip] (#3328)
Fix style issues in the changelog  [ci skip] (#3328)

Fixes various issues with inline code sections and PR references amongst
other things.
jakirkham/dask,ContinuumIO/dask,blaze/dask,dask/dask,mrocklin/dask,jcrist/dask,jakirkham/dask,mrocklin/dask,ContinuumIO/dask,jcrist/dask,dask/dask,blaze/dask