File Uploads Trigger Automatically Without Submission

### Issue: File Uploads Trigger Automatically Without Submission

**Description:**
Currently, in the note sharing web application, files are uploaded to Firebase automatically whenever a user selects a file for upload, without requiring explicit submission. To improve user control and prevent accidental uploads, the file upload process should occur only after the user clicks the submit function.

**Steps to Reproduce:**
1. Open the web application.
2. Navigate to the file upload section.
3. Select a file for upload.
5. Observe in the network tab that the file upload process initiates immediately upon file selection, before any explicit submission.

**Expected Behavior:**
- Users should be required to confirm or submit their file upload explicitly before the upload process begins.
- File uploads should only occur upon user confirmation or submission to ensure intentional actions and prevent accidental uploads.

**Proposed Solution:**
Modify the file upload functionality to execute only when the user clicks the submit button. This ensures that users have control over when their files are uploaded to Firebase and prevents accidental uploads. Additionally, consider updating the user interface to provide clear instructions and visual cues, guiding users through the upload process and informing them about the required actions to complete the upload.