Trying to install plugin (But not working)

I will yell you what am doing step by steep

i’m in my vps by SSH
i started with cd /var/discourse then ENTER
then i wrote this nano containers/app.yml and ENTER

am getting a very long menu, i dont now where i have to put this code

hooks:
after_code:
- exec:
cd: $home/plugins
cmd:
- mkdir -p plugins
- git clone GitHub - discourse/docker_manager: Plugin for use with discourse docker image · GitHub
- git clone GitHub - discourse/discourse-solved: Allow accepted answers on topics · GitHub

because i want to install solved plugin