add umaranis as fsharp maintainer (#775)
add umaranis as fsharp maintainer (#775)

Add umaranis as fsharp maintainer

Co-authored-by: Erik Schierboom <6e321e24be838c7616721fdb824f9c65569cbfd8@hotmail.com>

exercism/xfsharp,ErikSchierboom/fsharp,ErikSchierboom/xfsharp