Update contexts.md (#4588)
Update contexts.md (#4588)

Clarifying some grammar
0x00evil/phoenix,optikfluffel/phoenix,phoenixframework/phoenix,rafbgarcia/phoenix,nshafer/phoenix,0x00evil/phoenix,rafbgarcia/phoenix,optikfluffel/phoenix,0x00evil/phoenix,optikfluffel/phoenix,nshafer/phoenix,rafbgarcia/phoenix,nshafer/phoenix,phoenixframework/phoenix,phoenixframework/phoenix