Pass ESLint validations: File Example

Problem/Motivation

At #3417482: [Meta] Pass Eslint validations we are aiming to have all the eslint validation checks passing for the Examples module.

On this issue, we'll be focused on the file_example sub-module

Initial errors detected by 27/01/2024

/modules/file_example/file_example.links.menu.yml
  5:1  error  Expected indentation of 2 spaces but found 1 spaces  yml/indent
  6:1  error  Expected indentation of 2 spaces but found 1 spaces  yml/indent
  7:1  error  Expected indentation of 2 spaces but found 1 spaces  yml/indent
modules/file_example/file_example.permissions.yml
   9:9  error  Multiple spaces found before 'See private files in the File Example module demo.'    no-multi-spaces
  11:9  error  Multiple spaces found before 'See temporary files in the File Example module demo.'  no-multi-spaces
  13:9  error  Multiple spaces found before 'See session files in the File Example module demo.'    no-multi-spaces

Proposed resolution

1. Check the parent issue for detailed instructions about how to run eslint locally
2. Run eslint against the submodule: file_example
3. Fix the issues found and make a MR with the fixes.