Fix inconsistent capitalizations of "JavaScript"

[mtsknn]

Description

"Javascript"/"javascript" → "JavaScript"

Motivation and Context

Fixes #2398, or at least I can't find any more incorrect capitalizations. Well, there is https://github.com/MithrilJS/mithril.js/blob/next/render/tests/test-attributes.js#L175, but that's probably irrelevant (not a documentation file).

How Has This Been Tested?

Searched all files in VS Code using case-sensitive search terms "javascript" and "Javascript".

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation change

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have updated docs/changelog.md

[dead-claudia]

I could've sworn I caught everything, but apparently I did not. Thanks for the catch!