Fix improper format in Code Block in gdscript_basics.rst

[karmaral]

This PR closes #10460.

The code block wasn't rendering because it was missing its first blank line. I also deleted an extra stray line before it for consistency.

[mhilbrunner]

Thanks! Merged.

[karmaral]

Hey @mhilbrunner ! Quick question as I'm not entirely familiar with the workflow - I noticed the changes are on latest, should I make a PR that targets the stable branch too? Or does that get updated differently?

[tetrapod00]

@karmaral No need for you to make a PR that targets 4.3 or stable. As a general rule, changes always target the master branch, which becomes the latest branch on the website. Once the 4.4 release is finalized, the current state of master gets branched off into a 4.4 branch.

At some point, we'll manually backport or "cherrypick" a batch of the changes from latest to 4.3 (which is the source of truth) and then to stable (which is just a mirror of the current state of 4.3). There's no need for you to create another PR to do that yourself.

Historically, sometimes there is a wait of weeks or more before changes are actually cherrypicked, because the process is manual. But we're trying out a workflow that requires a little less manual work: #10361.