Merge #981: Fixed typos in CONTRIBUTING.md

c7a045f Fixed typos in CONTRIBUTING.md (Jon Marrs)

Pull request description:

  ### Description

  Fixed typos in CONTRIBUTING.md

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)

ACKs for top commit:
  thunderbiscuit:
    ACK c7a045f.

Tree-SHA512: de66f4be7c7fd608f5a74e51c5666f4fe6b962c5a8345c08c7b1da2551f81b9adfb28c58f0991ac6c985fa5c31f3eb7d17f99edf136b04945cefa24b28eaee19

Author: danielabrozzoni

CONTRIBUTING.md

@@ -28,7 +28,7 @@ The codebase is maintained using the "contributor workflow" where everyone
 without exception contributes patch proposals using "pull requests". This
 facilitates social contribution, easy testing and peer review.
 
-To contribute a patch, the worflow is a as follows:
+To contribute a patch, the workflow is as follows:
 
   1. Fork Repository
   2. Create topic branch