added Kotlin data types and control structures

[naeem4633]

Changes done to add Control Structures and Data Types for Kotlin.

What GitHub issue does this PR apply to?

Continues the work from #728.

What changed and why?

• Added a control_structures.json file inside the kotlin/1.5 directory containing the necessary content to define various control structures in Kotlin.
• Added a data_types.json file inside the kotlin/1.5 directory containing the necessary content to define various data types in Kotlin.

(If editing website code) Please add screenshots

Not applicable.

Checklist

• I claimed any associated issue(s) and they are not someone else's
• I have looked at documentation to ensure I made any revisions correctly
• I tested my changes locally to ensure they work
• For language files, I have validated the edited files are valid JSON and data shows up correctly
• For website code edits, I have added or edited any appropriate unit tests for my changes

Any additional comments or things to be aware of while reviewing?

None.

[geekygirlsarah]

I think these look good. I'll merge them in too!

Thanks for adding more Kotlin categories. I'm going to add Kotlin issues for things tonight.