Support application/x-www-form-urlencoded body

[elliots]

Description

Support form encoded body

Proposal

// handle body the same way as json in the client

// on fetch:
headers:{
  'Content-Type': 'application/x-www-form-urlencoded'
},    

body: new URLSearchParams({
   hello: 'world,
})

Checklist

• I’m willing to open a PR for this (see CONTRIBUTING.md)

[drwpow]

This has been added as of 0.6.0! 🎉 Please let me know if you are still encountering issues.