Add default value to sortBy variable (#87)

# Description

- Add default value to the sortBy variable ('hot')

#50

## Type of change

Please delete options that are not relevant.

- [x] New feature (non-breaking change which adds functionality)

# How Has This Been Tested?

Please describe the tests that you ran to verify the changes. Provide instructions so we can reproduce. Please also list any relevant details to your test configuration.

# Checklist

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that provde my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream modules

Reviewed-on: https://gitea.vylpes.xyz/RabbitLabs/random-bunny/pulls/87
Co-authored-by: Ethan Lane <ethan@vylpes.com>
Co-committed-by: Ethan Lane <ethan@vylpes.com>

src/index.ts

@@ -10,8 +10,8 @@ const sortable = [
     'top'
 ];
 
-export default async function randomBunny(subreddit: string, sortBy?: string): Promise<IReturnResult> {
-    if (!sortBy || !sortable.includes(sortBy)) sortBy = 'hot';
+export default async function randomBunny(subreddit: string, sortBy: string = 'hot'): Promise<IReturnResult> {
+    if (!sortable.includes(sortBy)) sortBy = 'hot';
 
     const result = await fetch(`https://reddit.com/r/${subreddit}/${sortBy}.json`);