Make the gitlab-ci.yml validation linter textarea bigger.

Description

When using the gitlab-ci.yml linter, the textarea is always at a minimum size. I use this to check for errors in my yaml file, I often drag the textarea to enlarge it and when I click 'validate', the page refreshes and the textarea goes back to the original (small) size.

Proposal

1. Make the default textarea height at least, 2x bigger
2. (More complex) Make it remember the last used size (if the user dragged it to be bigger).

Screenshot