Fix omit_containers example (#2279) [skip ci][ci skip]

Running ddev config changes the array equal to this change

docs/users/extend/config_yaml.md

@@ -27,7 +27,7 @@ the .ddev/config.yaml is the primary configuration for the project.
 | additional_fqdns | extra fully-qualified domain names | `additional_fqdns: ["example.com", "sub1.example.com"]` would provide http and https URLs for "example.com" and "sub1.example.com". Please take care with this because it can cause great confusion and adds extraneous items to your /etc/hosts file. |
 | upload_dir | Relative path to upload directory used by `ddev import-files` | |
 | working_dir | explicitly specify the working directory used by `ddev exec` and `ddev ssh` | `working_dir: { web:  "/var/www", db: "/etc" }` would set the working directories for the web and db containers. |
-| omit_containers | Allows the project to not load specified containers | For example, `omit_containers: ["db", dba", "ddev-ssh-agent"]`. Currently only these containers are supported. Some containers can also be omitted globally in the ~/.ddev/global_config.yaml and the result is additive; all containers named in both places will be omitted. Note that if you omit the "db" container, several standard features of ddev that access the database container will be unusuable. |
+| omit_containers | Allows the project to not load specified containers | For example, `omit_containers: [db, dba, ddev-ssh-agent]`. Currently only these containers are supported. Some containers can also be omitted globally in the ~/.ddev/global_config.yaml and the result is additive; all containers named in both places will be omitted. Note that if you omit the "db" container, several standard features of ddev that access the database container will be unusuable. |
 | nfs_mount_enabled | Allows using NFS to mount the project into the container for performance reasons | See [nfsmount_enabled documentation](../performance.md). This requires configuration on the host before it can be used. Note that project-level configuration of nfs_mount_enabled is unusual, and that if it's true in the global config, that overrides the project-specific nfs_mount_enabled|
 | host_https_port | Specify a specific and persistent https port for direct binding to the localhost interface | This is not commonly used, but a specific port can be provided here and the https URL will always remain the same. For example, if you put "59001", the project will always use "<https://127.0.0.1:59001".> for the localhost URL. (Note that the named URL is more commonly used and for most purposes is better.) If this is not set the port will change from `ddev start` to `ddev start` |
 | host_webserver_port | Specify a specific and persistent http port for direct binding to the localhost interface | This is not commonly used, but a specific port can be provided here and the https URL will always remain the same. For example, if you put "59000", the project will always use "<http://127.0.0.1:59000".> for the localhost URL. (Note that the named URL is more commonly used and for most purposes is better.) If this is not set the port will change from `ddev start` to `ddev start` |

pkg/ddevapp/templates.go

@@ -254,7 +254,7 @@ const ConfigInstructions = `
 # These values specify the destination directory for ddev ssh and the
 # directory in which commands passed into ddev exec are run.
 
-# omit_containers: ["db", dba", "ddev-ssh-agent"]
+# omit_containers: [db, dba, ddev-ssh-agent]
 # Currently only these containers are supported. Some containers can also be
 # omitted globally in the ~/.ddev/global_config.yaml. Note that if you omit
 # the "db" container, several standard features of ddev that access the