Fix a typo.

I kept seeing the project name as Supersonic when it's Supercronic.

crond/Dockerfile

@@ -5,16 +5,16 @@ WORKDIR /tmp
 RUN wget -q $URL && \
     echo "$SHA1SUM  supercronic-linux-amd64" > sha1.sum && \
     sha1sum -c sha1.sum && \
-    install -m 755 supercronic-linux-amd64 /usr/local/bin/supersonic && \
+    install -m 755 supercronic-linux-amd64 /usr/local/bin/supercronic && \
     touch /crontab
 
 FROM alpine:3.16
-COPY --from=downloader /usr/local/bin/supersonic /usr/local/bin/supersonic
+COPY --from=downloader /usr/local/bin/supercronic /usr/local/bin/supercronic
 COPY --from=downloader /crontab /crontab
 WORKDIR /tmp
 USER nobody
-CMD [ "supersonic", "/crontab" ]
-HEALTHCHECK CMD pgrep supersonic
-RUN supersonic -test /crontab
+CMD [ "supercronic", "/crontab" ]
+HEALTHCHECK CMD pgrep supercronic
+RUN supercronic -test /crontab
 ONBUILD COPY crontab /crontab
-ONBUILD RUN supersonic -test /crontab
+ONBUILD RUN supercronic -test /crontab

crond/README.md

 # Cron docker
 
 A Docker image for running a Cron daemon, actually running
-[Supersonic](https://github.com/aptible/supercronic).
+[Supercronic](https://github.com/aptible/supercronic).
 
 ## Usage
 
 There are possible usage patterns for this image. The first is using it in a
-multi-stage image build as the source of the `supersonic` binary to incorporate
+multi-stage image build as the source of the `supercronic` binary to incorporate
 in your own image like so:
 
 ```
-FROM registry.shore.co.il/cron as supersonic
+FROM registry.shore.co.il/cron as supercronic
 
 FROM alpine:latest
-COPY --from=supersonic /usr/local/bin/supersonic /usr/local/bin/
+COPY --from=supercronic /usr/local/bin/supercronic /usr/local/bin/
 ```
 
 The other pattern is building on top of this image to run some periodic tasks.