[ADD] company: Create form to add new company with job description upload #36

Create a form at /company/new/ to add a new company entry.

Add a new field job_description (FileField) to the CompanyModel to support file uploads.

Form fields:

• [name] Name (required)
• [package] Package
• [job_description] Job Description (file upload, required)
• [date] Date of Drive (optional)
• [process] Process (optional)
• [batch] Batch (default to 2022)