Fix typo (#791)

Small fix to change 'Jetbrain' to 'Jetbrains'

<!-- Explain the changes introduced in your PR -->

## Pull Request approval
Small fix to change 'Jetbrain' to 'Jetbrains'

You will need to get your PR approved by at least one member of the
Sourcegraph team. For reviews of docs formatting, styles, and component
usage, please tag the docs team via the #docs Slack channel.

Author: airamare01

docs/cody/use-cases/vsc-tutorial.mdx

@@ -102,7 +102,7 @@ To get started:
 3. Once you have found the command you want to reassign keybindings for, click on it to select it.
 4. Follow the instruction on screen to assign a new keybinding.
 
-### Getting Started (JetBrain)
+### Getting Started (JetBrains)
 
 To get started: 
 1. Click on the **IntelliJ IDEA** icon at the top menu bar and then click on **Keymap** from the dropdown to open the `Keymap Shortcuts Editor`.