Apply the changes from #840 to "hello-world/update.sh" (so they propagate properly)

See commit 63052cadffe8b17f0f362e4845504842be53a0ee.

hello-world/content.md

@@ -33,4 +33,4 @@ hello-world  latest  1815c82652c0  1.84 kB
 
 # How is this image created?
 
-This image is a prime example of using the [`scratch`](https://registry.hub.docker.com/_/scratch/) image effectively. See [`hello.asm`](%%GITHUB-REPO%%/blob/master/hello.asm) in %%GITHUB-REPO%% for the source code of the `hello` binary included in this image.
+This image is a prime example of using the [`scratch`](https://hub.docker.com/_/scratch/) image effectively. See [`hello.c`](%%GITHUB-REPO%%/blob/master/hello.c) in %%GITHUB-REPO%% for the source code of the `hello` binary included in this image.

hello-world/update.sh

@@ -23,5 +23,5 @@ echo
 cat <<'EOF'
 # How is this image created?
 
-This image is a prime example of using the [`scratch`](https://registry.hub.docker.com/_/scratch/) image effectively. See [`hello.asm`](%%GITHUB-REPO%%/blob/master/hello.asm) in %%GITHUB-REPO%% for the source code of the `hello` binary included in this image.
+This image is a prime example of using the [`scratch`](https://hub.docker.com/_/scratch/) image effectively. See [`hello.c`](%%GITHUB-REPO%%/blob/master/hello.c) in %%GITHUB-REPO%% for the source code of the `hello` binary included in this image.
 EOF