Add new limit option to limit the requested amount of posts from the Reddit API (#203)

- Add the limit option
- Valid number between 1 and 100
- Defaults to 100
- Updated documentation to mention this

#137

Reviewed-on: #203
Reviewed-by: VylpesTester <tester@vylpes.com>
Co-authored-by: Ethan Lane <ethan@vylpes.com>
Co-committed-by: Ethan Lane <ethan@vylpes.com>

src/contracts/ICliOptions.ts

@@ -3,5 +3,6 @@ export default interface ICliOptions {
     json?: boolean,
     sort: "new" | "hot" | "top",
     o?: string,
+    limit: number,
     queryMetadata?: boolean,
 }

src/contracts/QueryResult.ts

@@ -1,4 +1,5 @@
 export default interface QueryResult {
     subreddit: string,
     sortBy: string,
+    limit: number,
 }