docs(contributing): rename service to collector (#2453)

CONTRIBUTING.md

@@ -63,7 +63,7 @@ Follow the instructions below to create your PR.
 In the interest of keeping this repository clean and manageable, you should
 work from a fork. To create a fork, click the 'Fork' button at the top of the
 repository, then clone the fork locally using `git clone
-git@github.com:USERNAME/opentelemetry-service.git`.
+git@github.com:USERNAME/opentelemetry-collector.git`.
 
 You should also add this repository as an "upstream" repo to your local copy,
 in order to keep it up to date. You can add this as a remote like so:
@@ -110,7 +110,7 @@ Add your fork as an origin:
 
 ```shell
 $ cd $(go env GOPATH)/src/go.opentelemetry.io/collector
-$ git remote add fork git@github.com:YOUR_GITHUB_USERNAME/opentelemetry-service.git
+$ git remote add fork git@github.com:YOUR_GITHUB_USERNAME/opentelemetry-collector.git
 ```
 
 Run tests, fmt and lint: