Typos in chapter 9 of the spec

[leonhsl]

http://w3c.github.io/web-nfc/#the-nfcreader-and-nfcwriter-objects

"being dispatched"?

"The NFCReadingEvent is the event being dispatch on new NFC readings, "

"The NFCErrorEvent is the event being dispatch on errors, "

[leonhsl]

Step 9.12 in this section http://w3c.github.io/web-nfc/#the-push-method

Duplicate "is":

if device is is not officially supported by the NFC Forum, compatibility is "vendor" or "any".

[leonhsl]

http://w3c.github.io/web-nfc/#listening-for-content

Duplicate "attach an"?

the client needs to attach an attach an event listener for the "reading" event

[leonhsl]

http://w3c.github.io/web-nfc/#steps-receiving

"step 7 of the NFC listen algorithm" does not exist, instead, I guess we want to refer to step 3.2 and 3.5 of the NFC listen algorithm.

If there are any NFCReader instances in activated reader objects then UAs MUST listen to NDEF messages, according to step 7 of the NFC listen algorithm.

[kenchris]

Feel free to submit a PR for these