Update pubmatic.md

minor edits

Author: jeanstemp

dev-docs/bidders/pubmatic.md

@@ -38,7 +38,7 @@ If you upgrading from a Prebid version prior to 1.0, please reach out to your Pu
 | `dctr`		| optional | Deal Custom Targeting <br/> (Value configured only in the 1st adunit will be passed on. <br/> Values if present in subsequent adunits, will be ignored.) | `'key1=123|key2=345'` 	   | `string` |
 | `bcat`    | optional | Blocked IAB Categories  <br/> (Values from all slots will be combined and only unique values will be passed. An array of strings only. Each category should be a string of a length of more than 3 characters.) | `[ 'IAB1-5', 'IAB1-6', 'IAB1-7' ]`     | `array of strings` |
 | `deals`    | optional | PMP deals  <br/> (Values from each slot will be passed per slot. An array of strings only. Each deal-id should be a string of a length of more than 3 characters.) | `[ 'deal-id-5', 'deal-id-6', 'deal-id-7' ]`     | `array of strings` |
-| `outstreamAU`    | optional | Oustream AdUnit described in BlueBillyWig UI. It is mandatory field if mimeType is described as video and context is outstream i.e. for outstream videos           | `'renderer_test_pubmatic'`           | `string` |
+| `outstreamAU`    | optional | Oustream AdUnit described in Blue BillyWig UI. This field is mandatory if mimeType is described as video and context is outstream (i.e., for outstream videos)           | `'renderer_test_pubmatic'`           | `string` |
 
 ### Configuration