Now that you have a copy of your fork, there is work you will need to do to keep it current.
Inside your dev.to directory, add a remote to the official dev.to repo:
$ git remote add upstream https://github.com/thepracticaldev/dev.to.git
Do this prior to every time you create a branch for a PR:
Make sure you are on the master branch
$ git status
On branch master
Your branch is up-to-date with 'origin/master'.
If your aren't on master, resolve outstanding files / commits and checkout the master branch
$ git checkout master
Do a pull with rebase against upstream
$ git pull --rebase upstream master
This will pull down all of the changes to the official master branch, without making an additional commit in your local repo.
(Optional) Force push your updated master branch to your GitHub fork
$ git push origin master --force
This will overwrite the master branch of your fork.