Update fetch internships command to connection to other repos

[SilveerDusk]

Update fetch internships command to connection to other repos. start with adding https://github.com/SimplifyJobs/New-Grad-Positions so that people can check for new grad positions.

This means updating

const README_PATH = '../Summer2026-Internships/README.md';
const SECTION_OUTPUT_PATH = '../Summer2026-Internships/section_output.md';
const COMPANIES_OUTPUT_PATH = '../Summer2026-Internships/companies_output.md';

based on the section passed into FetchInternships.ts by fetchInternships.ts as a function parameter.