fixed verifying command in docs steps on windows

[qlrd]

What is this PR for?

A user on KruxBR found an issue on integrity verification step on Windows, more specifically, in powershell's Get-FileHash and Get-Content commands.

Since the Get-FileHash output a hash in upper case,when comparing with the output of Get-Content in lower case, the verification will result in a False value.

But this is a Negative False.

To fix this, we expanded the power shell command as well adding steps for a scrutiny procedure.

What is the purpose of this pull request?

• [ ] Bug fix
• [ ] New feature
• [x] Docs update
• [ ] Other

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.67%. Comparing base (f172162) to head (6100d0a). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #459 +/- ## ======================================= Coverage 94.67% 94.67% ======================================= Files 70 70 Lines 7575 7575 ======================================= Hits 7172 7172 Misses 403 403 ```

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[odudex]

Thank you!