fix more frontmatter keywords values (#439)

* fix format of frontmatter keyword entry in some .md files

Signed-off-by: Gaetan de Villele <gdevillele@gmail.com>

docs/recipes/apache.md

@@ -1,8 +1,7 @@
 ---
 description: Restricting access to your registry using an apache proxy
-keywords:
-- registry, on-prem, images, tags, repository, distribution, authentication, proxy,
-  apache, httpd, TLS, recipe, advanced
+keywords: registry, on-prem, images, tags, repository, distribution, authentication,
+  proxy, apache, httpd, TLS, recipe, advanced
 menu:
   main:
     parent: smn_recipes
@@ -213,4 +212,4 @@ Now, login with a "pull-only" user (using `testuser` and `testpassword`), then p
 
 Verify that the "pull-only" can NOT push:
 
-    docker push myregistrydomain.com:5043/test
+    docker push myregistrydomain.com:5043/test

docs/recipes/index.md

@@ -1,7 +1,6 @@
 ---
 description: Fun stuff to do with your registry
-keywords:
-- registry, on-prem, images, tags, repository, distribution, recipes, advanced
+keywords: registry, on-prem, images, tags, repository, distribution, recipes, advanced
 menu:
   main:
     parent: smn_recipes
@@ -34,4 +33,4 @@ At this point, it's assumed that:
  * [using Apache as an authenticating proxy](apache.md)
  * [using Nginx as an authenticating proxy](nginx.md)
  * [running a Registry on macOS](osx-setup-guide.md)
- * [mirror the Docker Hub](mirror.md)
+ * [mirror the Docker Hub](mirror.md)

docs/recipes/mirror.md

@@ -1,8 +1,7 @@
 ---
 description: Setting-up a local mirror for Docker Hub images
-keywords:
-- registry, on-prem, images, tags, repository, distribution, mirror, Hub, recipe,
-  advanced
+keywords: registry, on-prem, images, tags, repository, distribution, mirror, Hub,
+  recipe, advanced
 menu:
   main:
     parent: smn_recipes
@@ -74,4 +73,4 @@ For example, if your mirror is serving on `http://10.0.0.2:5000`, you would run:
 
     docker --registry-mirror=https://10.0.0.2:5000 daemon
 
-NOTE: Depending on your local host setup, you may be able to add the `--registry-mirror` option to the `DOCKER_OPTS` variable in `/etc/default/docker`.
+NOTE: Depending on your local host setup, you may be able to add the `--registry-mirror` option to the `DOCKER_OPTS` variable in `/etc/default/docker`.

docs/recipes/nginx.md

@@ -1,8 +1,7 @@
 ---
 description: Restricting access to your registry using a nginx proxy
-keywords:
-- registry, on-prem, images, tags, repository, distribution, nginx, proxy, authentication,
-  TLS, recipe, advanced
+keywords: registry, on-prem, images, tags, repository, distribution, nginx, proxy,
+  authentication, TLS, recipe, advanced
 menu:
   main:
     parent: smn_recipes
@@ -188,4 +187,4 @@ Login with a "push" authorized user (using `testuser` and `testpassword`), then
     docker login -u=testuser -p=testpassword -e=root@example.ch myregistrydomain.com:5043
     docker tag ubuntu myregistrydomain.com:5043/test
     docker push myregistrydomain.com:5043/test
-    docker pull myregistrydomain.com:5043/test
+    docker pull myregistrydomain.com:5043/test

docs/recipes/osx-setup-guide.md

@@ -1,7 +1,7 @@
 ---
 description: Explains how to run a registry on macOS
-keywords:
-- registry, on-prem, images, tags, repository, distribution, macOS, recipe, advanced
+keywords: registry, on-prem, images, tags, repository, distribution, macOS, recipe,
+  advanced
 menu:
   main:
     parent: smn_recipes
@@ -78,4 +78,4 @@ Start the Docker registry:
 
 ### Unloading the docker registry service
 
-    launchctl unload ~/Library/LaunchAgents/com.docker.registry.plist
+    launchctl unload ~/Library/LaunchAgents/com.docker.registry.plist