Make demo copy/pastable

Signed-off-by: Natalie Arellano <[email protected]>

Author: Natalie Arellano

content/docs/extension-author-guide/create-extension/build-dockerfile.md

@@ -93,5 +93,5 @@ Let's take a look at how the `samples/curl` extension fixes the error by switchi
 <!--+ if false+-->
 ---
 
-<a href="/docs/extension-author-guide/create-extension/run-dockerfile" class="button bg-pink">Next Step</a>
+<a href="/docs/extension-author-guide/create-extension/run-dockerfile-switch" class="button bg-pink">Next Step</a>
 <!--+ end +-->

content/docs/extension-author-guide/create-extension/setup-local-environment.md

@@ -72,8 +72,11 @@ We unset any custom lifecycle image that may have been provided to ensure that t
 
 <!-- test:exec -->
 ```bash
-git clone https://github.com/buildpacks/samples.git
-git checkout runext/update-samples # FIXME: remove when https://github.com/buildpacks/samples/pull/149 is merged
+# FIXME: remove branch when https://github.com/buildpacks/samples/pull/149 is merged
+git clone https://github.com/buildpacks/samples.git && \
+  cd samples && \
+  git checkout runext/update-samples && \
+  cd ..
 ```
 
 <!--+ if false +-->