📝 update HTTP verb capitalization in documentation

[techouse]

This pull request includes several changes to update HTTP method annotations in the documentation files to use uppercase versions. The changes ensure consistency and improve readability across the documentation.

Documentation updates:

• faq.md: Updated HTTP method annotations from lowercase to uppercase in compressRequest, ApiService, and TodosListService classes. [1] [2] [3]
• getting-started.md: Changed HTTP method annotations to uppercase in the list of annotations and provided examples. [1] [2]
• requests.md: Updated HTTP method annotations to uppercase in various examples and descriptions, including GET, POST, PUT, PATCH, DELETE, and HEAD. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.38%. Comparing base (fc60863) to head (df0f85e).
Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #654   +/-   ##
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  Coverage    93.38%   93.38%           
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  Files           21       21           
  Lines          499      499           
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  Hits           466      466           
  Misses          33       33           

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