Add a simple commands to add new link + check existing ones

[tarlepp]

So basically what I'm thinking is:

• Add a CLI command to add new link ./bin/console link:add <url_here>
• That command would add that to under current year + week in README.md
  • Title for link from URL title itself
  • Possible store static url content to year + week based directory in markdown format
• Add a CLI command to check current links ./bin/console link:check
  • This would check if link is still alive or not
  • Would compare existing markdown of that link within exising one
  • If there is differences ask user if this link is still valid or should it be updated
    • If still valid update stored markdown of that link
    • If not valid change that link target to point original stored markdown of link content

And the purpose for this is just to store that original link and contents of that, because sometimes people are deleting their posts from Internet and I still want to be able to read that deleted post.

Also we could add simple TravisCI test to do this all, and if some link fails within that second command build should fail - so that would indicate users to solve that issue before actual commit.

And after running those commands VCS will only contain changes of needed stuff - almost automatic :D