Documentation improvements - Startup Diagram, comments on key functions, and a "key files" section

[ankitpatel96]

Documentation

1. Wrote a startup procedure diagram. Describes how the collector starts
2. Variety of comments on less-commented functions
3. Pointing out some key files with some brief descriptions of how they fit into the broader collector

[codecov[bot]]

Codecov Report

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

Project coverage is 91.87%. Comparing base (7b046d9) to head (996ef1b). Report is 31 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10029      +/-   ##
==========================================
+ Coverage   91.65%   91.87%   +0.21%     
==========================================
  Files         360      360              
  Lines       16639    16725      +86     
==========================================
+ Hits        15251    15366     +115     
+ Misses       1053     1021      -32     
- Partials      335      338       +3     

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