DOCS: Fix some typos in the installation guide.

[MaxJPRey]

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Checklist

• I have tested my changes locally.
• I have added necessary documentation or updated existing documentation.
• I have followed the coding style guidelines of this project.
• I have added appropriate tests (unit, integration, system).
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.28%. Comparing base (3a67112) to head (b3f839d).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5607      +/-   ##
==========================================
+ Coverage   85.26%   85.28%   +0.01%     
==========================================
  Files         152      152              
  Lines       61016    61016              
==========================================
+ Hits        52025    52035      +10     
+ Misses       8991     8981      -10