Merge rust-bitcoin#4918: docs: remove redundant "a" in CONTRIBUTING.md

d9bdd60 docs: remove redundant "a" in CONTRIBUTING.md (Tomass)

Pull request description:

  fixed grammatical error by removing the redundant article "a" from the phrase "the workflow is a as follows" to make it grammatically correct as "the workflow is as follows"


ACKs for top commit:
  apoelstra:
    ACK d9bdd60; successfully ran local tests


Tree-SHA512: 4379e9639b64f41b4c8009fcd991f80acd0a8203719944deeabea18c1595e905465abcf27af7441768f3c92deb3e0286fa7ee0534d6188ecef4542f79f696f99

Author: apoelstra

CONTRIBUTING.md

@@ -74,7 +74,7 @@ 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 workflow is a as follows:
+To contribute a patch, the workflow is as follows:
 
 1. Fork Repository
 2. Create topic branch